What causes it?

Angina symptoms develop when the heart demands more oxygen than can be supplied, or when the blood supply drops below demand.

The most common cause of angina is atherosclerosis or coronary artery disease. This is a condition where one or more of the blood vessels supplying the heart becomes narrowed or blocked by fatty deposits. If the arteries become so blocked that they cannot supply enough blood to the heart muscle during exercise, abnormal levels of substances collect in the heart muscles and cause pain. This pain is angina.

Angina can also be caused by:

• Coronary artery spasm. A temporary narrowing of a coronary artery causes blood to slow or stop flowing through the artery. When the spasm stops, the artery and blood flow return to normal.

• Valvular heart disease
• Irregular heart rhythms
• Anaemia
• Polycythaemia
• Thyroid disease

Angina is more likely to occur when the heart is under pressure and needs more oxygen such as:

• During physical exercise
• Emotional upset/stress
• Cold air
• After a big meal
• Smoking

Angina can also occur at rest, however.

Who is most at risk?

Angina can occur at any age but is most common in older people. The condition is more common among men than women until after the menopause when the incidence of angina is equal in both sexes.

Risk factors for coronary heart disease include:

• Smoking
• High blood pressure
• Family history of heart disease
• Raised cholesterol
• Diabetes
• Sedentary lifestyle