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

S1 is the first heart sound that doctors can hear using a stethoscope. The vibrations that occur when the mitral and tricuspid valves in the heart close produce the S1 sound. There are two common ...

Your heart’s job is to keep your pulse steady to pump blood throughout your body. Sometimes your heart rate is slower when you’re relaxing, and sometimes it’s faster when you’re exercising or stressed ...