How frequently can you donate blood?

The answer is C, six times per year.

A healthy person at least 17 years old and weighing at least around 110 pounds can donate blood up to six times a year, or every 8 weeks. The body needs about 2 months to regenerate red blood cells, but other blood components such as platelets, the colorless clotting agents and plasma, the fluid that carries vital nutrients and comprises about 55 percent of blood volume, are regenerated much faster.

People can choose to donate just their plasma or platelets through a process called apheresis. Blood being pumped out of the donor is led through a centrifuge, which separates specific components out of the whole blood, leaving the rest to flow back into the donors other arm.

Platelets, which are formed in the bone marrow, are particularly valuable to cancer patients undergoing chemotherapy, radiation or bone marrow transplants, all of which drastically reduce their own platelet formation. While whole blood can be stored for up to 40 days under refrigeration and up to ten years if frozen, platelets only survive about 5 days outside of the body. People who donate their platelets can feel good to know they're going to help someone right away.

Resources

For more information on donating blood, visit the Red Cross.

Visit the American Association of Blood Banks for authoritative facts about blood, including a fascinating short history of blood transfusions.

September 14, 2002