In some adults, slightly hardened or oversized heart valves may cause the heart's circulating blood to make noises referred to as 'murmurs.' Hardened or narrowed heart valves may not be able to open completely, forcing blood to move through a smaller-than-normal opening.

When the heart muscle isn't receiving a sufficient supply of well oxygenated blood, a person may experience chest pain, or angina pectoris (an-JIE-nuh pek-TORE-iss).

Normally, the heart pumps blood through the arteries (ART-er-eez) and around the entire body. This pumping causes the blood to circulate under pressure, which is referred to as 'blood pressure.

Sometimes, children are born with heart abnormalities. Simple conditions such as innocent heart murmurs require no specific treatment and are generally outgrown by adulthood, while more complicated problems may require surgical repair.

When the heart cannot supply the body's other organs with a sufficient blood supply, a condition called congestive (kon-JESS-tiv) heart failure results.

Over time, fatty deposits can accumulate in the lining of the heart's major blood vessels, creating a condition called coronary artery disease. Although the process is generally gradual, these areas of build up may cause progressively more significant damage to the arterial vessels.

When the heart muscle incurs damage or has to work extra hard for a prolonged period of time, the heart itself may become enlarged. Minor enlargement may not prevent the heart from functioning correctly, but a significantly swollen one generally struggles to pump effectively.

The heart uses a pumping mechanism to send blood into the arteries (ART-er-eez) and throughout the body. This pumping, together with arterial (art-EAR-ee-all) resistance to the blood flow, creates a specific level of pressure in those vessels.

Mitral (MY-trahl) Valve Prolapse, or MVP (M-V-P) is a relatively common cause of systolic (sis-TALL-ik) heart murmur. In MVP, enlarged valves between the upper and lower left chambers of the heart close unevenly and collapse back into the upper atrium (AY-tree-um) chamber.

A pacemaker is a device that allows the heart to maintain a regular, continuous beat. The heart is equipped with a natural pacemaker that produces electrical signals, stimulating the heart muscle to beat at specific intervals.

Heart palpitations may be caused by several underlying factors. Sometimes, caffeine intake, emotional stress, or sudden physical exertion can stimulate a brief period of abnormally fast heartbeats.

A temporary lack of sufficient blood flow to the brain can result in a short loss of consciousness. This situation is referred to as 'syncope' (SIN-ko-pee).

When something causes an increased risk of heart and blood vessel disease, it's considered as a risk factor. Some risk factors are uncontrollable, while others are preventable or avoidable.

It's not uncommon to experience harmless episodes of breathlessness for brief periods. These spells can be caused by heavy exercise, sudden physical exertion, momentary anxiety, or surprise.

When the brain is prevented from receiving proper blood flow and oxygen, it can have a 'brain attack' or stroke. Strokes most often result from a traveling blood clot lodging in and completely blocking an artery to the brain, thereby cutting off blood and oxygen supplies.

Most cases of high blood pressure, or hypertension (HY-per-ten-shun), are due to unknown causes. Fortunately, however, the condition can often be successfully treated.

The circulatory system returns blood back to the heart by means of both surface and deep veins. Because of the distance from the heart to the legs, blood pressure in those veins can be particularly low.