What is a common cause of angina?

Angina is typically a symptom associated with insufficient blood flow to the heart muscle, often due to a lack of oxygen. When there is a reduction in the oxygen supply, which can happen during physical exertion, emotional stress, or due to narrowing of the coronary arteries, the heart experiences discomfort or pain. This sensation is known as angina pectoris.

The central factor contributing to angina is the mismatch between the heart's demand for oxygen and its ability to supply it, primarily due to reduced blood flow. Conditions like coronary artery disease can lead to plaque buildup, significantly compromising this blood supply, and therefore directly cause angina.

While excessive exercise and high cholesterol can contribute to conditions that may lead to angina, they are not the direct causes. Dehydration may also have effects on overall cardiovascular health, but it does not directly lead to reduced oxygen supply in the way that lack of oxygen does. Thus, it is the lack of oxygen to the heart that stands as the primary and direct cause of angina.