Q&A: Risks and benefits of giving blood?

Are there any health benefits or risks to donating blood? —D.A., Rockville, Md.

There are probably no benefits, except for the satisfaction of helping others, and the risks are minor. While some research suggests that giving blood might possibly help prevent cancer and heart disease by lowering the body's iron stores, that possibility is tenuous at best.

And donating is generally safe, though it occasionally causes nausea, dizziness, or fainting. To minimize those risks, drink lots of fluids and avoid strenuous activity for several hours after donating.