Pulse is the alternate expansion and recoil of an artery, which can be felt in an artery close to the body’s surface because of the rhythmic ejection of blood from the heart into the aorta, which causes an increase and decrease of pressure in the vessel. Pulse provides important information about the heart action, blood vessels, and circulation. A fast pulse rate may indicate the presence of an infarction or dehydration. In a medical emergency, the pressure of a pulse will help determine if a person’s heart is pumping.