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 ...

You're curled up on the couch, finally relaxing after a long day when suddenly, your heart starts racing. You're obviously ...

A fast heartbeat can be caused by emotions like stress or anxiety. Dehydration, or drinking caffeine or other stimulants, can ...

Tom Brownlee does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their ...