Heart disease

Heart disease is a broad term for conditions that affect the heart and the blood vessels that supply it. In everyday use it most often refers to coronary artery disease, in which fatty deposits narrow the arteries feeding the heart muscle. The wider family of cardiovascular diseases also includes heart failure, abnormal heart rhythms (arrhythmias), diseases of the heart valves and congenital conditions present from birth.

Cardiovascular disease is one of the leading causes of death worldwide. Its scale has driven decades of research, and the payoff has been substantial: many of its major risk factors are known, and a large share of cases are preventable or can be delayed through lifestyle and medical care.

How the heart works

The heart is a muscular pump with four chambers. The right side sends oxygen-poor blood to the lungs, and the left side pumps oxygen-rich blood around the body. Like any muscle, the heart needs its own blood supply, delivered by the coronary arteries. Electrical signals coordinate each heartbeat, and valves keep blood flowing in one direction. Problems in any of these systems can produce disease.

Coronary artery disease and heart attacks

Coronary artery disease develops when plaque — deposits of cholesterol, fat and other substances — builds up inside the coronary arteries. This process, called atherosclerosis, narrows the vessels and reduces blood flow. When a plaque ruptures, a blood clot can block the artery entirely, cutting off oxygen to part of the heart muscle. That is a heart attack, or myocardial infarction.

Angina is chest pain or discomfort that occurs when the heart muscle is temporarily short of oxygen, often during exertion, and eases with rest. It is a warning sign that should prompt medical assessment.

Other forms of heart disease

Heart failure

Despite the name, heart failure does not mean the heart has stopped. It means the heart cannot pump as efficiently as it should, so fluid can build up in the lungs and legs and everyday activities become more tiring. It often results from earlier damage such as a heart attack or long-standing high blood pressure.

Arrhythmias

Disturbances of the heart's electrical rhythm, ranging from harmless extra beats to serious conditions such as atrial fibrillation, which raises the risk of stroke.

Valve disease

Valves may narrow or leak, forcing the heart to work harder. Some valve problems are present from birth; others develop with age or after infection.

Congenital heart disease

Structural heart problems present at birth. Advances in surgery mean many people born with these conditions now live full adult lives.

Risk factors

Risk factors fall into two broad groups. Those we cannot change include age, sex (men tend to develop the disease earlier, though risk rises in women after menopause) and family history. Those we can influence are the focus of prevention:

These factors tend to cluster and reinforce one another, which is why addressing several at once is more effective than tackling one in isolation.

Symptoms and warning signs

Heart disease can be silent for years. When symptoms appear, common ones include chest pain or pressure, shortness of breath, fatigue, palpitations, dizziness and swelling in the legs or ankles. In a heart attack, symptoms may include crushing chest pain spreading to the arm, neck or jaw, along with sweating, nausea and breathlessness. Women, older adults and people with diabetes sometimes experience subtler symptoms, which can delay recognition. Sudden severe symptoms warrant emergency help.

Prevention and treatment

Prevention rests largely on the modifiable factors above. A diet rich in vegetables, fruit, whole grains and unsaturated fats, regular physical activity, not smoking, maintaining a healthy weight and managing stress all reduce risk. Controlling blood pressure, cholesterol and blood sugar — often with medication — is central for people at higher risk.

Treatments depend on the condition. They include medications such as statins for cholesterol, drugs to lower blood pressure, and medicines to reduce clotting or slow the heart. Procedures include angioplasty, in which a balloon and often a small mesh tube called a stent reopen a narrowed artery, and coronary bypass surgery, which routes blood around a blockage. Devices such as pacemakers and implantable defibrillators manage rhythm problems, and rehabilitation programmes help people recover and adopt healthier habits.

Common misconceptions

A frequent myth is that heart disease mainly affects men. It is a leading cause of death in women too, and women may present with atypical symptoms. Another is that only older people are at risk; plaques can begin forming in youth, and risk accumulates over a lifetime. People also sometimes assume that a "clean" family history means they are safe, overlooking the large role of lifestyle. Finally, heart disease is not an inevitable part of ageing — much of the risk can be lowered.

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