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11.3.4 Health and Fitness


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Donating Blood

What precautions should I take after donating blood?

Be sure to take the following precautions:

Drink an extra four glasses of non-alcoholic liquids... Because you could experience dizziness or loss of strength, use caution if you plan to do anything that could put you or others at risk of harm. For any hazardous occupation or hobby, follow applicable safety recommendations regarding your return to these activities following a blood donation."

Any donation facility will give you a personal number to identify your donation. If you remember important health information that you may have not given, or if you get sick or otherwise decide your blood may not be safe to give to another person, you can call the toll free number on the info page they will give you.

It has been found:

  • People who smoke soon after giving blood are more likely to feel the effects of nicotine and therefore faint.
  • People who take alcohol within a few hours of giving blood are more likely to feel faint because alcohol dilates the blood vessels. This causes less blood to be available to circulate to the brain leading to dizziness and fainting.
  • Being in a hot room also causes the blood vessels to dilate and thus has a similar effect to alcohol.
  • Rushing about or vigorous exercise can also produce similar effects.
  • Missing meals and not replacing fluids means a delay in the recovery from blood donation.
  • Standing still for long periods of time can lead to pooling of blood in the legs, a situation similar to soldiers on parade. This reduces the amount of blood available to the brain.
  • If you rush about, miss a meal, have a "liquid lunch", a cigarette, or get overheated you may feel faint even if you gave blood several hours ago.

How often can I donate blood?

If you don't change your life in a way that could prevent you from donating, you can safely donate every eight weeks.

When you give blood, you temporarily lose some fluid which your body replaces within 24 hours. Do not exercise right after the donation and avoid strenuous activity for five hours after donating. Give your body a day (24 hours) to replace the volume you donated. Please consult with your DAME to ensure it is appropriate for you to donate.

How long should I wait to fly after donating blood?

There is no specific policy on this, only guidelines. The primary concern is your increased risk of becoming hypoxic. The usual blood loss to an otherwise healthy pilot by donating blood is well-compensated by increased heart and respiration rates. But there is the possibility of some impairment in hypoxic conditions (altitudes, cabin or otherwise, above 10,000 feet) for 8-12 hours after making the donation (more if the donor is in poor physical condition).

The military requires pilots to wait 72 hours after giving blood, and many corporate flight departments follow this guideline. Others don't allow their pilots to donate blood. Therefore, as a guideline, flying within 24 hours of donating blood may not be totally safe and is not worth the risk. If you are not in good health or you are slightly anaemic then check with your DAME.