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 ...

Have you ever experienced a sudden increase in heart rate while sitting, lying in bed or even during a calm moment at work? The feeling can be unsettling as it often comes without warning or a clear ...

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 ...