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A normal heart rate is somewhere between sixty to one hundred beats per minute.

Bradycardia is the term for a heart rate slower than about sixty beats per minute, but bradycardia doesn't necessarily mean you're not in perfectly good health. In well-conditioned athletes, bradycardia is a result of being in such good shape that the heart beats more efficiently, and so it doesn't need to beat as quickly.

An athlete may have a heart rate as slow as thirty and not show any signs of problems. Also, deep relaxation, such as sleep, slows the heart down.

Unfortunately, bradycardia can also be caused by certain medications, by other disorders such as hyperthyroidism, and by dysfunction of the sinus node. I don't mean the hollow space behind your nose, but the node inside your heart. The sinus node powers your heart by electrical impulses.

Dysfunction of the sinus node then can cause the heart to beat too slowly to keep up with your body's need for blood. Lightheadedness, weakness, and fainting are symptoms that a heart may be beating too slowly. In such cases, doctors will remove problem medications, correct the underlying disorder, or insert a pacemaker that fills in for the sinus node.

If symptomatic bradycardia goes untreated, it could lead to death, but that's easy enough to prevent--just go see your doctor.

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