What is the primary cause of angina?

The primary cause of angina is decreased oxygen supply to the heart. Angina occurs when the heart muscle does not receive enough oxygen-rich blood to meet its demands, which often results from an imbalance between the oxygen supply and the oxygen demand of the heart. When the coronary arteries are narrowed or blocked—often due to atherosclerosis—this can lead to insufficient blood flow during times of increased physical or emotional stress, or even at rest in some cases.

While high blood pressure can contribute to increased workload on the heart and may be a risk factor for coronary artery disease, it is not the direct cause of angina. Similarly, coronary artery blockage is certainly a contributing factor to decreased oxygen supply; however, it is essential to understand that the primary mechanism underlying the sensation of pain in angina is indeed the reduced oxygen supply to the cardiac muscle itself. Lastly, increased physical activity can precipitate angina in individuals with compromised coronary circulation, but it is not the root cause. It simply highlights a situation where the existing problem (decreased oxygen supply) becomes evident.