Your heart beats about 100,000 times a day. Sometimes it beats faster and sometimes more slowly, depending on what you're doing and whether, for instance, you're all worked up about something. So ...

In atrial fibrillation, the heartbeat is very irregular and often fast. Doctors use medicines to control both the speed and ...

You know the feeling. When you first see your crush and your head starts spinning, your palms get sweaty, and your heart begins beating a mile a minute. Is this love? Or is it … an arrhythmia? The ...

The heart is the body's hardest-working muscle. Whether you're awake or asleep, or exercising or resting, your heart is always at work. It pumps blood through arteries to deliver oxygen to organs and ...

A new study shows that the sinoatrial node (SAN) -- a small but powerful structure in the human heart that serves as its natural pacemaker and initiates every normal heartbeat -- runs on different ...

Pregnancy is often marked by unexpected changes in your body that can catch you off guard. You may expect some of these changes, but others can cause worry. Feeling your heart beat faster, even when ...

Yes, allergies can increase your heart rate. This may occur as a symptom of allergic rhinitis or as a side effect of an allergy medication. Learn more about prevention and treatment options. Your ...