Angina is typically caused by reduced blood flow to the heart muscle, resulting in decreased oxygen supply. The most common cause of angina is coronary artery disease, which occurs when the arteries that supply blood to the heart become narrowed or blocked due to a buildup of plaque (atherosclerosis). Other possible causes of angina include:

- Spasm of the coronary arteries
- Blood clots
- Inflammation of the coronary arteries
- Coronary artery anomalies
- Anemia
- High blood pressure
- Heart valve disease

Risk factors for developing angina include smoking, high cholesterol, high blood pressure, diabetes, obesity, lack of physical activity, and a family history of heart disease.