I’m often awakened by the sound of my own heartbeat. Is that serious? —B.F.S., Niles, Ill.

Probably not. The most likely cause is simply that your mattress is amplifying the sound, especially if you sleep on your left side. If so, try a different position, with your ear not pressed against the pillow or mattress. If that doesn’t help, ask your doctor about anemia or heart-valve disease, both of which can cause an unusually loud pulse as the heart struggles to supply enough blood and oxygen.

Read more on how to keep your heart healthy, and see our information on the benefits and risks of anemia drugs.