The heart is a complex organ that pumps blood throughout the body.

A heart that is not healthy does not always produce symptoms. However, certain signs and symptoms can indicate a problem with the heart.

This article describes the anatomy of the heart and how it works. We also provide tips on how to tell if the heart is healthy and outline some symptoms of various heart conditions.

The heart is responsible for pumping blood throughout the body. To do this, the heart fills with blood and then contracts to push the blood through the circulatory system. Electrical impulses tell the heart how often to contract or “beat.”

The right side of the heart receives blood from the veins and pumps it on toward the lungs. Here, the blood receives oxygen and removes carbon dioxide for the lungs to breathe out. The left side of the heart then receives the oxygenated blood from the lungs and pumps it through arteries to the rest of the body.

The interactive BodyMap diagram below shows the location of the heart in the body. Press on the buttons to interact, including adding and removing layers, and moving around the diagram.

The heart is in the chest, slightly left of center. It sits behind the breastbone and between the lungs.

The heart has four distinct chambers. The left and right atria are at the top, and the left and right ventricles at the bottom. The septum is a wall of tissue that separates the left and right chambers.

The heart also has four valves:

  • The pulmonic valve opens and closes to regulate blood flow from the right ventricle to the pulmonary artery (lungs).
  • The aortic valve opens and closes to regulate oxygenated blood from the left ventricle to the aorta (the largest artery in the body).
  • The mitral valve opens and closes to regulate oxygenated blood flow from the left atrium to the left ventricle.
  • The tricuspid valve opens and closes to regulate blood flow from the right atrium to the right ventricle.

The heart also contains the following three types of tissue:

  • Myocardium: Muscular tissue that causes the heart to contract and relax.
  • Endocardium: A thin tissue that covers the chambers and valves of the heart.
  • Pericardium: A thin, sack-like layer that provides support and protection for the heart while reducing friction between the beating heart and its surrounding tissues.

Heart disease is the umbrella term for a range of conditions that affect the heart.

Some people may have “silent” heart disease. This means that a person will not develop symptoms until they experience a cardiac event, such as a heart attack, arrhythmia, or heart failure.

Signs of arrhythmia

Heart arrhythmia is the medical term for a heartbeat that is too fast, too slow, or irregular. Arrhythmias occur when the electrical impulses that control the heartbeat malfunction. This can give rise to a fluttering sensation in the chest, which doctors refer to as palpitations.

A persistent arrhythmia can affect heart function, leading to more severe symptoms, such as:

Palpitations are not always a sign of an underlying heart condition. They can occur as a result of anxiety or the use of caffeine and other stimulants. However, a person should see a doctor if they experience frequent arrhythmias, or they experience other signs and symptoms of a heart problem.

Signs of heart failure

Heart failure is where the heart is no longer effective at pumping blood around the body. According to the American Heart Association (AHA), some common signs of heart failure include:

  • an unexplained increase in heart rate
  • tiredness or fatigue
  • confusion or inability to think clearly
  • nausea
  • loss of appetite
  • swelling in the feet, legs, hands or other areas of the body with unexplained weight gain
  • shortness of breath
  • sleeping on extra pillows
  • waking up at night short of breath
  • a persistent cough that may produce pink-tinged mucus

A heart attack is a medical emergency in which the blood supply to the heart becomes blocked. Without sufficient blood supply, the heart muscles become damaged and begin to die.

According to the Centers for Disease Control and Prevention (CDC), the five most common signs of a heart attack include:

  • chest pain or discomfort
  • pain or discomfort in one or both shoulders or arms
  • discomfort or pain in the jaw, back or neck
  • shortness of breath
  • feeling weak, lightheaded, or faint

According to the American Heart Association (AHA), the symptoms of a heart attack may vary between biological males and females. Both sexes are likely to experience chest discomfort or pain. However, biological females are more likely to experience the following additional symptoms:

  • shortness of breath
  • nausea or vomiting
  • pain in the back or jaw

A person should call 911 or seek emergency care if they or someone they are with is experiencing symptoms of a heart attack.

Heart disease is an umbrella term that can refer to several different heart conditions. The most common is coronary artery disease (CAD). In CAD, the major arteries that supply the heart become blocked or damaged, thereby increasing the risk of a heart attack.

Other conditions related to heart disease include:

  • Angina: Pain in the chest due to lack of blood to the heart.
  • Aortic aneurysm and dissection: A condition in which the aorta becomes enlarged or torn.
  • Arrhythmias: A heartbeat that is irregular or abnormally fast or slow.
  • Atherosclerosis: A buildup of fatty deposits, or plaque, in the arteries.
  • Atrial fibrillation: Rapid heartbeat in the upper chambers of the heart that can increase the risk of stroke.
  • Cardiomyopathy: Enlargement or weakening of the heart muscle.
  • Congenital heart defects: Heart abnormalities present from birth.
  • Heart failure: Inability of the heart to effectively pump blood around the body or inability of the heart to relax.
  • Marfan syndrome: A genetic condition that affects connective tissues throughout the body, including the aorta.
  • Peripheral artery disease (PAD): A narrowing of the arteries that reduces blood flow to the limbs.
  • Pulmonary hypertension: High blood pressure in the artery that leads from the heart to the lungs.
  • Rheumatic heart disease: A potential complication of rheumatic fever that can lead to blockages of the heart valves.
  • Valvular heart disease: The valves in the heart do not open fully or leak when they close.

The American Society of Echocardiography also identifies several health conditions that can impact the heart. They include:

A person should talk to their doctor if they experience signs or symptoms of the following conditions:

  • heart arrhythmia
  • heart disease
  • any underlying medical condition that could affect the heart

A person should call 911 or seek emergency care immediately if they experience signs or symptoms of a heart attack. Prompt treatment is crucial to restoring blood flow to the heart.

The heart is a complex organ with several chambers, valves, and tissues that work together to pump blood around the body. Electrical impulses regulate the timing of each heartbeat.

Sometimes, heart disease is silent, meaning a person may not develop any symptoms until they experience a cardiac event, such as arrhythmia or heart attack. People must see a doctor if they experience any concerns relating to their heart.

Some possible signs of heart disease include palpitations, lightheadedness, and fatigue. While these can be symptoms of other conditions, it is best to see a doctor for a diagnosis. Treatments can help to slow the progression of heart disease and reduce the risk of complications.