According to the American Red Cross, there's a 97% chance that someone you know will need a blood transfusion. Blood donors — especially donors with certain blood types — are always in demand.

Who Can Donate Blood?

To donate blood, the American Red Cross requires that people be at least 17 years old and weigh more than 110 pounds. (In some states, the age is 16 with a parent's permission.)

Donors must be in good health and will be screened for certain medical conditions, such as anemia. Donors who meet these requirements can give blood every 56 days.

Before Donating

Blood donation starts before you walk in the door of the blood bank. Eat a normal breakfast or lunch — this is not a good time to skip meals — but stay away from fatty foods like burgers or fries. And be sure to drink plenty of water, milk, or other liquids.

Before donating, you'll need to answer some questions about your medical history, and have your blood pressure and blood count checked. The medical history includes questions that help blood bank staff decide if there's a risk that donors might have an infection that could be transmitted in their blood. So they'll probably ask about any recent travel, infections, medicines, and health problems.

Donated blood gets tested for viruses, including HIV (the virus that causes AIDS), hepatitis B, hepatitis C, syphilis, and West Nile virus. If any of these things are found, the blood is destroyed. Because blood can be infected with bacteria as well as viruses, certain blood components are tested for contamination with bacteria as well.

What's It Like to Donate Blood?

The actual donation takes about 10 minutes. It's a lot like getting a blood test. After you're done, you'll want to sit and rest for a few minutes, drink lots of fluids, and take it easy the rest of the day (no hard workouts!). Your local blood bank or Red Cross can give you more information on what it's like and what you need to do.

Are There Any Risks?

A person can't get an infection or disease from giving blood. The needles and other equipment used are sterile and they're used only on one person and then thrown away. The U.S. Food and Drug Administration (FDA) regulates U.S. blood banks. All blood centers must pass regular inspections in order to continue their operations.

Sometimes people who donate blood notice a few minor side effects like nausea, lightheadedness, dizziness, or fainting, but these symptoms usually go away quickly.

The donor's body usually replaces the liquid part of blood (plasma) within 72 hours after giving blood. It generally takes about 4-8 weeks to regenerate the red blood cells lost during a blood donation. An iron-fortified diet plus daily iron tablets can help rebuild a donor's red blood supply.

The Red Cross estimates that 15% of all blood donors in the United States are high school or college students. If you are eligible and wish to donate blood, contact your local blood bank or the American Red Cross for more information on what's involved. You could save someone's life.

Reviewed by: Maureen F. Edelson, MD
Date reviewed: May 2012