Why is my heart rate high?

Ask the doctors

Q.As expected, my heart rate rises when I exercise. But sometimes it seems elevated for no apparent reason. Why might this happen?

A. When at rest, the average adult's heart beats between 60 and 100 times each minute. Your heart can speed up for many different reasons — including, as you've noted, physical activity. Other triggers are also temporary, such as stress, smoking, or caffeine or alcohol use. Certain medications, including those that treat colds, asthma, mood disorders, and high blood pressure, can also elevate your heart rate.

But a higher-than-normal heart rate can also result from a serious health condition such as anemia, overactive thyroid, or heart disease. Seek immediate medical care if your heart rate seems high and you're also short of breath, dizzy, lightheaded, or weak, or if you have chest pain. In the absence of urgent symptoms, make an appointment to talk to your doctor about what else might be contributing to a higher heart rate.