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 fast heartbeat can be caused by emotions like stress or anxiety. Dehydration, or drinking caffeine or other stimulants, can make your heart beat fast. More serious conditions like heart arrhythmia ...

That little number on your fitness tracker might be more important than you realize. Your resting heart rate isn’t just some random vital sign. It’s essentially a window into how efficiently your ...

A cooler bedroom might be better for older sleepers than previously thought. Researchers found that keeping nighttime temperatures at 75°F reduced stress responses and helped the heart work more ...