Home Table of Contents

11.1.1 Basic Health


Back Next
Diet and Exercise

Proper diet and exercise are the mainstays for a healthy lifestyle. The basic tenets to gradual weight loss and good health include developing healthy eating habits and increasing daily physical activity.

Excessive body weight contributes to snoring and obstructive sleep apnea, in addition to being a major influence on general health and well-being. Obstructive sleep apnea occurs in about 50-60 percent of those who are obese. Consult a physician - men over age 40; women over 50; people with (or at risk for) chronic health problems such as heart disease, diabetes, or obesity.


Design a plan that you will enjoy and be able to follow. Your exercise regimen should push you to work hard without being dangerous. Alternate different activities like running, swimming and weightlifting to avoid getting bored.

  • Start out slowly and build up activity gradually over a period of months. This will help avoid soreness and injury.
  • Try to accumulate 30 minutes or more of moderate-intensity cardiovascular activity each day. You can do all 30 minutes together or through short bouts of intermittent activity (e.g. 10 minutes at a time).
  • Add strength-developing exercises at least twice per week.
  • Incorporate physical activity into your day (walk to the office or store, take the stairs instead of the elevator, walk or jog at lunch time, etc.)
  • Make leisure time active - garden, walk, ride a bike with family and friends, participate in an exercise class, join in a sports activity.
  • Select activities you enjoy, find satisfying, and that give you a feeling of accomplishment. Success leads to increased motivation to be physically active.
  • Be sure your activities are compatible with your age and physical condition.
  • Make it convenient to be active. Choose activities that are readily accessible (right outside your door) like gardening, walking, or jogging.
  • Try "active commuting." Cycle, walk, or in-line skate to work or to the store.
  • Make your activity enjoyable - listen to music, include family and friends, etc.

For those who are already moderately active, increase the duration and intensity for additional benefits.


Enjoy a variety of foods that will provide essential nutrients.

  • Three-quarters of your lunch and dinner should be vegetables, fruits, cereals, breads, and other grain products. Snack on fruits and vegetables. Eat lots of dark green and orange vegetables. Choose whole-grain and enriched products more often.
  • Choose lower-fat dairy products, leaner meats and alternatives, and foods prepared with little or no fat. Shop for low fat (2% or less) or fat-free products such as milk, yogurt, and cottage cheese. Eat smaller portions of leaner meats, poultry, and fish; remove visible fat from meat and the skin from poultry. Limit the use of extra fat like butter, margarine, and oil. Choose more peas, beans, and lentils.
  • Limit salt, caffeine, and alcohol. Minimize the consumption of salt. Cut down on added sugar such as jams, etc. Limit beverages with a high caffeine content (tea, sodas, chocolate drinks) and caffeinated coffee to two cups per day. Minimize alcohol to one to two drinks per day.
  • Limit consumption of snack foods such as cookies, donuts, pies, cakes, potato chips, etc. They are high in salt, sugar, fat, and calories, and low in nutritional value.
  • Eat in moderation. If you are not hungry, don't eat.

A condition where the sugar content of the blood has fallen to a dangerously low level. Symptoms include;

  • Physical or mental tiredness.
  • Lightheadedness.
  • Collapse and unconsciousness.

Initially the brain and nervous systems are affected which manifest as personality changes such as:

  • Anger.
  • Lack of ability to exercise judgement.
  • Poor decision making.

Hypoglycaemia can occur as a result of a diabetic taking an overdose of insulin. In fit people hypoglycaemia can occur when:

  • No food has been eaten for a few hours.
  • Subjected to sudden mental anxiety or physical exercise.

A quick fix to hypoglycaemia is to take a sweet drink or eat sweets.

Coronary Risk Factors

Coronary heart disease affects many people and may cause angina (chest pain) and heart attack. Risk factors for heart disease include smoking, diabetes, obesity, family history and age. By following a healthy lifestyle and taking medicines as prescribed by your doctor, you can reduce your overall risk of developing coronary heart disease.

Coronary heart disease risk factors are conditions or habits that raise your risk of coronary heart disease (CHD) and heart attack. These risk factors also increase the chance that existing CHD will worsen.

CHD, also called coronary artery disease, is a condition in which a waxy substance called plaque (plak) builds up on the inner walls of the coronary arteries. These arteries supply oxygen-rich blood to your heart muscle.

Plaque narrows the arteries and reduces blood flow to your heart muscle. Reduced blood flow can cause chest pain, especially when you're active. Eventually, an area of plaque can rupture (break open). This causes a blood clot to form on the surface of the plaque.

If the clot becomes large enough, it can block the flow of oxygen-rich blood to the portion of heart muscle fed by the artery. Blocked blood flow to the heart muscle causes a heart attack.

There are many known CHD risk factors. You can control some risk factors, but not others. Risk factors you can control include:

  • High blood cholesterol and triglyceride (tri-GLIS-er-ide) levels (a type of fat found in the blood)
  • High blood pressure
  • Diabetes and prediabetesexternal link icon
  • Overweight and obesity
  • Smoking
  • Lack of physical activity
  • Unhealthy diet
  • Stress

The risk factors you can't control are:

  • age
  • gender
  • family history of CHD.

Many people have at least one CHD risk factor. Your risk of CHD and heart attack increases with the number of risk factors you have and their severity. Also, some risk factors put you at greater risk of CHD and heart attack than others. Examples of these risk factors include smoking and diabetes.

Many CHD risk factors start during childhood. This is even more common now because many children are overweight and don't get enough physical activity. Some CHD risk factors can even develop within the first 10 years of life.

Blood Pressure

The maximum arterial pressure is achieved when the left ventricle contracts to force blood out of the heart. Known as the Systolic Pressure, this is the pressure at which the blood leaves the heart through the Aorta. When the heart relaxes, the pressure in the left ventricle will fall and the valve from the heart is closed off. Elastic recoil in the Aorta and the arteries maintains the pressure so that a steady flow of blood is achieved towards the capillaries.

During the Systolic phase:

  • The ventricles contract.
  • Pressure in the heart increases.
  • The aortic valve is forced open.
  • Blood is forced down the aorta.
  • The aorta stretches to make room for the blood.

The minimum pressure in the arteries is the Diastolic Pressure. This pressure reflects the resistance of the small arteries and capillaries to the blood flow. This resistance is the load against which the heart must work.

During the Diastolic phase:

  • The ventricles relax.
  • The pressure within the heart decreases.
  • The aortic valve is forced shut.
  • The elastic walls of the aorta recoil and return to their original position.
  • Even though the heart is at rest the blood is still propelled through the rest of the body.

Blood pressure is determined by using a sphygmomanometer where the blood pressure is given in mmHg. Measurement is taken from the upper arm in a sitting position. Typically, the values of blood pressure are given as two figures eg 120 over 80 meaning:

  • Systolic 120 mmHg
  • Diastolic 80 mmHg

The World Health Organisation (WHO) classification of Blood Pressure (mmHg) is listed below:


  • Below normal: < 100
  • Normal: 100 - 139
  • Borderline: 140 - 159
  • Hypertension: > 159


  • Below normal: < 60
  • Normal: 60 - 89
  • Borderline: 90 - 94
  • Hypertension: > 94

If the systolic and diastolic pressures are high when the body is at rest then this is an indication that the heart is working hard at pumping blood. This high blood pressure increases the risk of stroke and coronary heart disease especially when the blood pressure is higher than 140/90. Long term hypertension imposes strain on the cardio-vascular system that in turn can lead to heart failure.

The cause of high blood pressure is generally unknown but can be linked to:

  • Moderate to excessive intake of alcohol.
  • Smoking.
  • Obesity.
  • Salt in the diet.
  • Genetic factors.

Hypertension has a reputation as the silent killer because of the lack of warning of impending heart failure or heart attack.

Orthostatic Hypotension

Orthostasis means upright posture, and hypotension means low blood pressure. Orthostatic hypotension consists of symptoms of dizziness, faintness or light-headedness that appear on standing, and are caused by low blood pressure. Symptoms that often accompany orthostatic hypotension include chest pain, trouble holding the urine, impotence, and dry skin from loss through sweating.

Causes of Orthostatic Hypotension

Blood pressure is maintained by a combination of several factors. The heart is the central pump, and a weak or irregular heart can cause orthostasis. Conditions such as arrhythmia heart failure, deconditioning, and pregnancy are examples where the heart may not be able to provide an adequate blood pressure. The heart pumps blood, and if there is too little blood volume (anaemia, dehydration, dialysis), the pressure drops. The blood vessels in the body also can constrict to raise blood pressure, and if this action is paralysed, blood pressure may fall. Heat, such as a hot shower or from a fever, can also dilate blood vessels and cause orthostasis.

Both Hypo- and Hypertension can lead to the loss of a pilot's licence.

Coronary Heart Disease

Coronary heart disease (CHD) kills an estimated 10,000,000 people worldwide. CHD is a general term that refers to any disease that results in a restriction or blockage of the coronary blood supply to part of the hearts wall. Any restriction or blockage causes a partial or total deprivation of oxygen to the affected part. This may cause death in the muscle cells. Any sudden irreversible damage of this kind is termed a myocardial infarction. Where a large part of the heart is affected then a person may die. If only a small region is affected then the person may make a complete recovery.

The first two branches of the aorta are the left and right coronary arteries. These vessels spread out over the surface of the heart and divide into a dense network of capillaries supplying the muscle of the atria and ventricles.


The build up of a fatty material in the lining of the coronary arteries causes them to narrow. Initially the fatty material lines the inner coat of the artery wall. As time passes, lipid and cholesterol molecules from the blood enlarge the fatty material. Eventually, calcium deposits harden this fatty material. The larger these deposits become, the more the restriction in the blood vessel. The heart has to work harder to force blood through the arteries which in turn may cause the blood pressure to rise.

Plaque build up in the arteries which leads to coronary artery disease and symptoms of angina.

Where CHD develops it normally takes one of three forms:

  • Angina: Suffered by people who have their coronary arteries narrowed by atherosclerosis. The main symptom is severe pain in the centre of the chest radiating out to the left arm and up to the neck and jaws. Normally brought about by exertion or stress, the pain goes when the sufferer relaxes. There is no death of muscle tissue involved. During exercise or stress the heart beats faster and the demand for oxygen by the cardiac muscle cells increases. This demand cannot be met by the reduced flow through the narrowed coronary arteries and so angina results.
  • Heart Attack: Also known as Myocardial Infarction or Coronary Thrombosis. The fatty lining on the inside of an artery makes the surface uneven and this results in a disturbance of the smooth blood flow. This provides sites where blood can clot slowly (thrombus).
  • If a clot breaks loose it follows the blood flow until it reaches a narrower blood vessel. This can severely restrict or even stop the blood flow. This blockage causes the heart muscle to be starved of oxygen and leads to a myocardial infarction. Sudden and severe heart pain results which may be fatal.
  • Heart Failure: The blockage of a main coronary artery leads to gradual damage of heart muscle with the result that the heart becomes weaker and fails to pump blood efficiently.
Risk Factors of Coronary Heart Disease

The main risk factors in their order of importance are:

  • Family history
  • Smoking
  • Raised blood pressure
  • Raised blood cholesterol
  • Lack of exercise
  • Diabetes

Other conditions such as obesity are not fully understood.

Reducing the Risk of Coronary Heart Disease By avoiding the main risk factors the risk of CHD can be minimised. You can help yourself by:

  • Stop smoking!
  • Leading a less stressful lifestyle.
  • Being careful with the diet, eating a low cholesterol and low fat diet.
  • Keeping your weight to a normal Body Mass Index.
  • Exercising at least three times a week for a minimum of 20 minutes. The exercise must be vigorous enough to double the pulse rate.
Detection and Treatment of CHD

Tests do not give an accurate indication of the health of the coronary arteries. An ECG can give some indication of the electrical activity of the heart muscle to show abnormalities such as an infarct, or narrowing of the arteries. For partial blockages arteriography would have to be used.


A stroke occurs when the blood supply to an area of the brain is cut off. Two types of stroke can occur:

  • Haemorrhagic: An artery in the brain bursts so that blood leaks into brain tissue - a brain haemorrhage, or
  • Ischemic: There is a blockage due to atherosclerosis.

A blood deficiency involving an abnormal reduction of the haemoglobin content of the red blood cells. These are the cells that carry oxygen to the various locations of the body. Those who are anaemic develop symptoms caused by the inadequate delivery of oxygen to their body tissues. Symptoms include low energy, dizziness, shortness of breath, pallor and digestive disorders.


Any food that is eaten in excess of that required is stored as fat. Obesity is associated with a high fat intake in the diet and lack of exercise. Obesity increases the risk of developing the following diseases:

  • Diabetes.
  • Hypertension.
  • Coronary heart disease.
  • Arthritis.
  • Cancer - especially of the colon, rectum, prostrate in men and uterus, cervix and breast in women.
  • Stroke.

Obesity also increases the likelihood of developing hernia, varicose veins and gallstones.

Obesity is defined as when a person:

  • Is 20% or more above the recommended weight for height.
  • Has a Body Mass Index greater than 30.

To lose weight a person must reduce their intake of food.

Body Mass Index

The Body Mass Index (BMI) is calculated as:

BMI = Body mass (Kg) ÷ Height (m²)


  • Underweight: < 20
  • Acceptable: 20 - 25
  • Overweight: > 25 - 30
  • Obese: > 30


  • Underweight: < 19
  • Acceptable: 19 - 24
  • Overweight: > 24 - 29
  • Obese: > 29

Diabetes is a metabolic disorder that changes the way the body breaks down sugars and starches. In normal people insulin, which is a hormone produced in the pancreas, helps to convert sugar to energy. This is stored by the body cells or used instantaneously. Diabetes is diagnosed as:

  • Non-Insulin Dependent Diabetes: The pancreas produces insulin but the body is not able to make use of it effectively.
  • Insulin Dependent Diabetes: The sufferer must have insulin injections because of a lack of insulin being produced.

Non-insulin-dependent diabetes is linked to a person's body weight; most non-insulin diabetics are 20% over their ideal body weight. Non-insulin diabetes can disappear when weight is lost.

Coronary Problems

A contributor to heart failure. Obesity causes changes in the heart's left ventricle, which raise the risk of sudden death.

Exercise Exercise does not help a person lose weight although it is an excellent way to reduce the risk of CHD. To be effective exercise has to be regular:

  • It must be sufficient to double the resting pulse.
  • Be carried out for at least 20 minutes three times a week.
Digestive Problems

Most diseases caused by contaminated water may also be acquired from contaminated food. This is the principal source of simple diarrhoea and food poisoning. In tropical countries it is not unusual for human excreta to be used as fertiliser. Irrigation of crops is by the use of open springs or sewers. Do not eat raw vegetables or fruit unless you peel them yourself. Avoid salads as they are usually washed in the local water. Milk and milk products can also be the cause of certain ailments.

Food Poisoning

Food poisoning is a general term applied to some gastrointestinal infections. The risk to flight safety is by the sudden onset of incapacitating symptoms. Food poisoning does occasionally occur on board aircraft or during flight and flight crew should not consume food from the same source prior to or during a flight.


Diarrhoea (travellers' diarrhoea) is a worldwide illness where the body excretes watery stools. The rapid dehydration that occurs may cause serious flight safety problems.


Cholera is an acute enteric infection caused by Vibrio Cholerae. Spread by the intake of water and foods contaminated by the excrement of infected persons. Untreated, mortality may exceed 50 per cent. Control is by purification of water supplies and proper sewage disposal. Cholera vaccine provides some protection for a period of six months.

Amoebic Dysentery

Amoebiasis Infection is by cysts from faeces of infected persons and is transmitted by hand to mouth, polluted water, and contaminated raw vegetables. Severe complications can affect the liver and lungs. The disease may be encountered anywhere in the world.

Tropical Diseases

Where public health control is poor personal protection from Tropical Diseases must rely on preventive measures and personal hygiene.

The term tropical disease refers to diseases or conditions encountered in areas with high temperature and humidity. This is assumed to be an area bounded by the Tropics of Cancer and Capricorn.

Tropical diseases are well understood. They are preventable and curable by modern drugs. If proper attention is given to personal hygiene combined with simple safeguards, there is no reason why problems should occur. Flight crew have to be alert and must follow:

  • Simple rules of hygiene.
  • Sanitary precautions.

Water Contaminated drinking water is one of the most frequent sources of intestinal infection such as:

  • Diarrhoea
  • Dysentery
  • Typhoid and paratyphoid fevers
  • Cholera
  • Schistosomiasis and worm infections.

These can develop into chronic diseases for which the cure is difficult. All can be prevented if sensible precautions are taken with regard to water and food. Do not:

  • Drink water straight from the tap.
  • Have drinks with ice cubes.
  • Brush the teeth with tap water.
  • Drink water from pre-opened bottles.

To purify water boil it for 3 - 5 minutes. Hot tea or coffee and undiluted citrus fruit drinks are also safe. If water cannot be boiled purify with a chemical tablet. Drinks from well-reputed manufacturers that are bottled under strict licensing control are usually safe. Outdoor swimming in salt water is safe, except where beaches are next to freshwater outlets. Freshwater can be the source of serious tropical disease and bathing should be avoided.

Insects and Insect vectors

High temperatures, humidity and long hot seasons ensure that insects flourish in tropical environments. Exposure to insects is predominantly due to outdoor or primitive living conditions. Insects can affect the health of a person in the following manner:

  • By transmitting or disseminating the disease.
  • Some insects are parasitic in or on the human body.
  • Some are directly poisonous in that they may inject powerful, even lethal irritants or venom.

Mosquito-Borne diseases The most important of mosquito-borne diseases is malaria. Mosquitoes require blood in order to reproduce. Other important mosquito-borne diseases include:

  • Yellow Fever
  • Dengue Fever
  • Filariasis

Malaria is an acute recurrent, febrile disease characterised by chills followed by high fever and sweating. The incubation period is usually eight to nine days but can be up to 12 months. Deaths due to malaria are reported every year among international travellers. These occur because:

  • Travellers are unaware of, or underestimate, the danger of contracting malaria abroad
  • Lack of prevention measures such as taking the required medication

Malaria still kills more people than any other tropical disease.

Diseases Transmitted by Flies

Gastro-intestinal diseases are transmitted by the housefly in unhygienic or unsanitary environmental conditions.

Biting flies are responsible for dissemination of bartonellosis, pappataci fever and Leishmaniasis that may be prevalent in certain tropical areas.

Tsetse flies are vectors of trypanosomiasis (African sleeping sickness) in central Africa.

Other Insects

Assassin bugs (Reduviidae) are vectors of Chagas disease found in Central and South American areas.

Fleas are vectors of plague, murine or endemic typhus and some tapeworms.

Ticks are vectors of such diseases as Rocky Mountain spotted fever, Q fever, Colorado tick fever, encephalitis and tularaemia, and can cause tick paralysis. Soft ticks transmit relapsing fevers.

Mites and lice are transmitters of typhus and encephalitis fevers.

Cockroaches and bedbugs are looked upon with suspicion because they usually indicate unsanitary environments but they are not natural vectors of disease.


Inflammation of the liver caused by infectious or toxic agents. Infectious agents include viruses, spirochetes protozoa and bacteria. The incubation period is two to six weeks and the infection can be prevented by immune serum globulin injections.


Medical requirements for immunisation of flight crew on international flights differ from country to country. Requirements are usually company dependent.


Rabies is an infectious fatal disease spread to humans by the bite of an infected animal. The incubation period for rabies is between 3 weeks to 120 days. The disease is nearly always fatal unless a vaccine is given. Stay away from all animals especially cats and dogs. Rabies is a common problem in many countries around the world.


The official Civil Aviation Safety Regulations explains everything in regards to pregnancy within the aviation industry.

CASR 67.235 Suspension of medical certificates - pregnancy

(1) A medical certificate held by a pregnant woman who holds, or is an applicant for, a licence is taken to be suspended:

  1. during the period beginning immediately after the end of the 30th week of gestation and ending when a DAME certifies that she is fully recovered following delivery or the termination of the pregnancy; or
  2. if in a particular case CASA directs in writing that a different period should apply - during the period so directed by CASA; or
  3. if, before the start of the period mentioned in paragraph (a), the pregnancy ends in miscarriage or premature labour, or is terminated by medical intervention - from the time of the miscarriage, premature labour or intervention until a DAME certifies that the woman is fully recovered.

  4. Note: This regulation does not preclude a pilot who is pregnant from undertaking or receiving instruction in a flight simulator at any stage of the pilot's pregnancy.

(2) Despite subregulation (1), a pregnant woman who holds an air traffic controller licence may continue to exercise the privileges of the licence until the end of the 38th week of gestation if:

  1. the medical practitioner who is attending the woman certifies her continued medical fitness to do so each week beginning at the 31st week of gestation; and
  2. a DAME certifies the woman's continuing fitness to do so each week beginning at the 31st week of gestation; and
  3. another person who holds an air traffic controller licence, and is medically fit and able to take over responsibility for the function, is on duty and available at the times when she does so.

Headaches and Migraines

Migraine headaches can vary from person to person, but they typically last from four hours up to 72 hours. Some people get them several times per month, while others experience them much less frequently. Many migraine sufferers report throbbing or pulsating pain on one side of the head, blurred vision, sensitivity to light and sound, nausea, and vomiting.

Roughly one in five migraine sufferers experience an aura, or visual or sensory disturbance, before the onset of the headache. Examples of an aura include: flashes of light, loss of vision, zig-zag lines, pins and needles in an arm or leg, and speech and language problems.

Several risk factors have been identified that increase a person's chance of having migraines:

  • Family history: A significant majority of migraine sufferers have a family history of migraine attacks. For a person who has one or more first-degree relatives with migraine headaches, the likelihood rises substantially.
  • Age: Migraines typically affect people between the ages of 15-55. Most people have had their first attack by 40 years old.
  • Gender: Women are more likely to suffer from migraines than men.
  • Certain medical conditions: depression, anxiety, stroke, epilepsy, and high blood pressure are all associated with migraine headaches.
  • Hormonal changes: Women who suffer from migraines often find that the headaches have a pattern of recurrence just before or shortly after the onset of menstruation. The headaches may also change during pregnancy and/or menopause.

Migraines are vascular headaches but the exact cause is not fully understood. Some researchers believe that migraines occur when there are abnormal changes in the brain. When these changes occur, inflammation causes blood vessels to swell and press on nerves, which can result in pain.

Researchers have learned that certain triggers can set off migraine attacks. These triggers vary from person to person and can include: sleep disturbances, stress, weather changes, low blood sugar, dehydration, bright lights and loud noises, hormonal changes, foods that contain aspartame, foods that contain tyramine (fava beans, aged cheeses, soy products, etc.), caffeine, and alcohol.

Unfortunately, migraines have no known cure, but they can be managed effectively with the help of a health care provider. A variety of drugs can be used for pain relief and for prevention. Lifestyle changes are often recommended to identify and eliminate possible triggers that can set off an attack.

Until recently there have been no treatments available to treat people who suffer from chronic migraines. Recently, a new medication has become available specifically to treat chronic migraine headaches, called onabotulinumtoxinA (Botox). Chronic migraine sufferers can derive significant benefit from this new form of therapy.

Chronic migraine sufferers have also found relief in certain vitamins and other homeopathic remedies. But patients should check with their doctors for proper treatment protocols.

Smoking Tobacco

In the 1950s the link between smoking and lung cancer was recognised. In the 1960's, smoking was found to be a risk factor in CHD. Tobacco smoke is composed of:

  • Mainstream Smoke Smoke from the filter or mouth end of a cigarette.
  • Sidestream Smoke Smoke from the burning tip.

Approximately 85% of smoke in a room is sidestream smoke. Most of the 4000 different chemicals in cigarette smoke are found in a higher concentration in the sidestream smoke than the mainstream smoke. This must put others as well as the smoker at a greater risk of developing smoking related diseases. This is known as passive smoking.

Three main components of cigarette smoke pose a threat to the human being:

  • Tar
  • Carbon Monoxide
  • Nicotine

Tar is implicated in the blocking of the bronchiole tree and tarring of the alveoli. Sufferers experience difficulty in breathing because of the blockage of the airways and the progressive destruction of the alveoli. The blockage of the airways is caused by chronic bronchitis. Where a person has been smoking for a long time the chronic bronchitis can be accompanied by emphysema:

  • Chronic Bronchitis: The cleaning action of the lungs is inhibited by the tar in tobacco smoke. As the tar passes through to the lungs through the airways more mucus is secreted. This mucus accumulates in the bronchiole tree and may block the passage of air. Any dirt, bacteria or virus will collect in the mucus - this is the cause of what is known as "smoker's cough" .
  • Emphysema: Where the lung is affected by chronic bronchitis infection will become more commonplace. Inflammation occurs and an enzyme called elastase is produced. This enzyme destroys the elasticity of the alveoli which eventually burst. Thus there is less surface area for any gaseous exchange. In extreme cases a person will need continuous oxygen to stay alive.
Carbon Monoxide

Carbon monoxide (CO) is a product of the incomplete combustion of carbon compounds and is absorbed by inhalation. The relative toxicity of CO increases with altitude. Carbon Monoxide (CO) is absorbed by the blood in the alveoli and competes with oxygen for haemoglobin. The haemoglobin has a greater affinity for the CO than it does oxygen (approximately 200 times). The stable compound carboxy-haemoglobin is formed and because of this the amount of oxygen available for absorption is reduced by as much as 10%.

CO is deadly; being colourless, odourless and tasteless. It has a four hour half-life in air.

Carbon monoxide does not naturally occur in any quantity in the atmosphere. Its effects can be cumulative and are not easily corrected. Oxygen does not bring quick relief and several days may be required to rid the body completely of carbon monoxide. The presence of carbon monoxide results in hypoxia where it can have the same effect as an altitude increase of 8,000 to 10,000 feet.

The symptoms of carbon monoxide poisoning are headache, dizziness, weakness, nausea, rapid heart beat, respiratory failure and death. After death a person shows a redness in the lips and cheeks.


Nicotine stimulates the sympathetic nervous system by reducing the diameter of the arteries which stimulates the release of adrenaline from the adrenal glands. Nicotine is absorbed into the blood and will reach the brain within a few seconds. The release of adrenaline increases the heart rate and blood pressure. The narrowing of the arteries decreases the blood supply to the extremities such as the hands and feet. This lack of Oxygen can lead to the amputation of limbs due to the onset of gangrene.

Alcohol, Drugs and Medication

The term drug is a difficult one to define; in the widest sense a drug is a chemical substance which is taken into the body or applied to the skin. More commonly the term is used to describe substances which interfere with some aspect of the body's metabolism.

These drugs are taken to alter the:

  • progress of a disease, such as a painkiller or antibiotic.
  • working of the nervous system such as LSD, Heroin or even Alcohol.

General Health The person who, for whatever reason, does not feel well should not fly. General discomfort is not conducive to safe flying.

Self-medication is also hazardous and the best recommendation to flyers is not to take any drug and fly. Drugs and flying do not mix. The side effects of most medications can be disabling in the air. If illness or pain requires treatment then a pilot will not perform normal flying tasks well.


Water is a critical element of the body, and keeping the body adequately hydrated is a must to allow the body to function. Up to 75% of the body's weight is made up of water. Most of the water is found within the cells of the body (intracellular space). The rest is found in the extracellular space, which consists of the blood vessels (intravascular space) and the spaces between cells (interstitial space).

  • The body needs water to function.
  • Dehydration occurs when water intake is less than water loss.
  • Symptoms range from mild to life-threatening.
  • The young and the elderly are especially susceptible to dehydration.

Dehydration occurs when the amount of water leaving the body is greater than the amount being taken in. The body is very dynamic and always changing. This is especially true with water in the body. We lose water routinely when we:

  • breathe and humidified air leaves the body (this can be seen on a cold day when you can see your breath in the air, which is just water that has been exhaled).
  • sweat to cool the body.
  • eliminate waste by urinating or having a bowel movement.

The formula for daily fluid requirements depends upon an individual's weight. Normally, fluid and weight are calculated using the metric system; however, below is the approximation in imperial (American) units.

Body weight Daily fluid requirements (approximate):

  • 10 pounds 15 ounces
  • 20 pounds 30 ounces
  • 30 pounds 40 ounces
  • 40 pounds 45 ounces
  • 50 pounds 50 ounces
  • 75 pounds 55 ounces
  • 100 pounds 50 ounces
  • 150 pounds 65 ounces
  • 200 pounds 70 ounces

If you would like to calculate your body weight and daily fluid requirements using the metric system, please use this formula.

  • For the first 10kg (kilogram) of body weight the daily fluid intake required is 100cc (or mL) per kg.
  • For the next 10kg of body weight, the fluid required is an additional 50 cc/kg.
  • For every additional kg of body weight, an additional 10cc/kg is required.

This is the basic body requirement. More fluid would be needed to replace excess sweating from exercise or fever, fluid loss from vomiting, and diarrhea or increased urine production.

Blood Donations

Donating blood is safe and simple. We use only totally sterile disposable blood bags and needles. The actual donation process works like this:

You will complete a donor registration form that includes your name, address and a few other details. You will be asked a few questions about your health. You will go through a simple medical checkup including blood pressure, and pulse. A drop of blood will be obtained from your finger tip to test for Hemoglobin and your group. You will proceed to a donor bed where your arm will be cleaned with antiseptic. During the donation process, you will donate 350ml or 450ml depending on your weight. After the process is over, you will rest for about 5 minutes.

The procedure is done by skilled, specially trained doctors/nurses and takes three to eight minutes. However, from start to finish (filling form, post donation rest, etc) the entire process should take 30 to 40 minutes.

A donor after having given blood voluntarily gets a feeling of great pleasure, peace and bliss. Soon, within a period of 24-48 hours, the same amount of new blood gets formed in the body, which helps the donor in many ways. His own body resistance improves, the circulation improves, and he himself feels healthier than before.

The donor needs rest, preferably lying down, so that the amount of blood that has been donated soon gets poured into the circulation from the body pools in a natural way. The donor should take it easy for about 10-15 minutes. A healthy person can donate after every 56 days. Three months time between donations is a very safe interval.

CASA recommends that holders of all classes of medical certificates should usually refrain from exercising privileges of any aviation licence for at least 24 hours after a routine blood donation. In other or unusual circumstances, consultation with a DAME or contact with the Aviation Medicine Section is advisable before resuming exercise of privileges.


Natural changes in cells may slow them down or alter their capacity, he says. Most people reach their peak functioning at around age 30. How soon you notice age-related changes in stamina, strength, or sensory perception will vary based on your personal health choices, your medical history, and your genetics. Some age-related complaints are common, and some symptoms aren't caused by aging at all.

Here is some advice on how to tell the difference:


By around age 40, almost everyone will be reaching for reading glasses. Presbyopia occurs when the lens becomes stiff and won't adjust to refocus from distance to near vision. Cataracts, or clouding of the lens, may begin to affect your vision when you reach your 60s. Long-term exposure to sunlight increases the risk of cataracts, which can be corrected through surgery to replace the lens.

If you notice you have worse peripheral than central vision, or the reverse, you could have a serious eye condition that requires treatment. Glaucoma occurs when the pressure in the eye increases and causes damage to the optic nerve. Two forms of macular degeneration affect the center of the retina, leading to a loss of central vision.

The bottom line: If you feel you're having blurred vision or vision loss, you should get your eyes examined.

Hearing Loss

About a third of people who are 60 or older have some hearing loss. This condition, known as presbycusis, may be due to the loss of sensory receptors in the inner ear. At first, some sounds may seem muffled, and high-pitched voices may be harder to understand. Men tend to have more hearing loss than women.

Pain, drainage from the ear, or a rapid loss of hearing could be a sign of a tumor or infection. If the hearing in one ear is noticeably worse than the other, that is also a reason to have it examined. If people just notice, "I'm not hearing quite as well as I did a few years ago," that's the aging process. If I don't hear as well this week as I did last week, that's not the aging process.

Decrease in Strength or Stamina

With age, we lose muscle tissue and our muscles become more rigid and less toned. Weight training and stretching improve strength and flexibility, though we can't completely counteract this natural course of aging.

Our organs lose their extra reserve, too. The walls of the heart become thicker, the arteries are stiffer, and the heart rate slows as we age. Aging of the heart is a major reason it may be harder to exercise vigorously when we are older as we could when we were 20. Yet maintaining regular aerobic activity -- even just walking -- can improve our stamina.

When should you worry? Get an immediate evaluation if you have chest pain, especially with dizziness, nausea, shortness of breath, or fainting. Those are possible signs of a heart attack. Problems with your heart rate could cause lightheadedness, dizziness, or fatigue.

One in 10 people age 65 or older have anemia, or a low level of oxygen-carrying red blood cells. It can cause fatigue and can be treated with iron supplements or medications to spur the body to produce more red blood cells.

High Blood Pressure

Aging is not a disease, but our body's changes make us vulnerable to some medical conditions.

One example is essential hypertension, or high blood pressure. The exact cause of essential hypertension is not known. There are several factors that play a role including genetic factors, obesity, salt intake and aging. Blood vessels tend to become less elastic with age, and this stiffness may contribute to high blood pressure.

More than half of people 60 and older have high blood pressure - a reading of 140 (systolic) over 90 (diastolic) or higher.

A low-sodium diet, exercise, and maintaining a healthy weight can help prevent high blood pressure.

Memory Loss

Can't remember where you put your keys? Forgot the name of an acquaintance you haven't seen in a while? Those momentary lapses are normal.

No need to worry, unless the forgetfulness is impairing your daily life. Many of us have a memory complaint, but it's not dementia or disease.

Generally, information processing slows as we grow older, and older people have more trouble multitasking. But there's a lot of variability in cognitive function. Not surprisingly, for example, older adults typically outperform young adults in their knowledge of the world.

The red flag for dementia related to Alzheimer's disease is the inability to learn and retain new information. Problems with episodic memory are a sign of mild cognitive impairment that could be a precursor of the disease, according to new guidelines for diagnosing Alzheimer's.

People with Alzheimer's have other cognitive deficits, as well, such as trouble with language or recognizing objects, Trojanowski says. Biomarkers detected through imaging or a test of cerebrospinal fluid can aid in the diagnosis of Alzheimer's.

If you have memory problems and you have a family history of Alzheimer's disease, you may want to be evaluated. Alzheimer's disease rarely occurs among people who are younger than 65. About one in eight people aged 65-74 have Alzheimer's, and 43% of people who are older than 85 have Alzheimer's.

Ageing Summary

There are many different signs and symptoms of aging. Most of these develop gradually and are very diverse, but it should be remembered that it is not possible to diagnose aging based on isolated signs and symptoms alone. Different people possess widely varying degrees of these signs and symptoms. Some of these include:

  • An overall decrease in energy and vigor.
  • The tendency to become easily tired.
  • Changes in sleeping patterns.
  • Decreased memory.
  • Behavioural changes.
  • Skin and hair changes such as wrinkles, brown spots on the skin, loss of skin elasticity, and hair loss affecting the limbs.
  • Changes in hair colour.
  • A loss or decrease in vision and hearing.
  • Changes in bowel function.
  • Decrease in libido.
  • Sexual dysfunction.
  • Urinary problems such as incontinence, dribbling, and changes in frequency of urination.
  • Changes in menstrual cycle.
  • Abdominal obesity and inability to lose weight.

Sooner or later, many people develop one or more of the degenerative diseases of aging, such as:

  • Alzheimer's disease.
  • Stroke.
  • Heart attack.
  • Cancer.
  • Osteoporosis.
  • Diabetes Mellitus.
  • Parkinson's disease.
  • Arthritis.
  • Cataracts.
  • Glaucoma.
  • Hearing loss.