"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Your heartbeat lets you know how hard your heart is working to circulate blood throughout your body.

Add Yahoo as a preferred source to see more of our stories on Google. How often do you think about your heartbeat? Probably not on the regular, unless you notice it when you’re working out or anxious.

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

Heart palpitations are a common but usually harmless symptom. However, persistent heart palpitations or other severe symptoms, such as chest pain, shortness of breath, or fainting, require prompt ...