What Are the Dangers of Giving Blood?

Blood donation is a safe, sterile procedure performed in a controlled environment. There are no dangers to giving blood, as long as the donor has been honest during the pre-donation health screening and follows some simple pre- and post-donation instructions.

Deferral

• Deferral occurs when a donor is not fit to give blood, either temporarily or permanently. If a donor misrepresents information--about weight, for example, or general health--during a screening to avoid a deferral, she may, after donating blood, become faint or suffer health consequences from giving up a pint of blood. Blood centers also ask health questions to protect the blood supply, and if the donor is not honest about such things as risky sexual behavior, or time spent in certain countries, he may expose others to infectious diseases such as HIV or mad cow disease.

Dehydration

• Dehydration is one of the main reasons donors feel poorly after donation. It's recommended that donors eat breakfast and lunch normally before donation, and drink plenty of fluids before and after donation. Not having eaten or drunk enough can cause a donor to feel dizzy, lightheaded or faint after donation. Since this happens within five or 10 minutes after donation ends, the staff at the donation center usually prefers that donors remain there briefly for observation.

Bruising

• Some donors report bruising at the site of donation. Usually the site is covered by gauze and an elastic bandage, with instructions to leave the bandage on for a few hours. Ice can help reduce pain and bruising if it occurs.

Weakness

• Whole blood donors should refrain from exercise or other strenuous physical activity for the rest of the day, and should not lift anything heavy with their donation arm. Recovery time is shorter for platelet and plasma donors, as their red blood cells are returned to them during donation.

Other Side Effects

• In a 2008 study of 16- and 17-year-old whole blood donors published in the Journal of the American Medical Association, that donation group is shown to have a higher risk of complications. These include pallor (pale color), diaphoresis (excessive sweating) and lightheadedness, and fainting spells ranging from less than a minute to longer than a minute with convulsions. These side effects were very rare.