There are many factors that can cause low blood pressure, usually divided into primary and secondary factors. Primary low blood pressure, for example, low blood pressure due to physiological reasons, and the genetic factors of thin body shape have a certain relationship. Secondary hypotension refers to the state of low blood pressure caused by certain diseases, which are usually divided into two types: 1, short-term rapid onset of low blood pressure, such as extensive trauma, infection, dehydration, allergies, massive bleeding, caused by the sudden decrease in blood pressure. 2, slow onset of low blood pressure gradually aggravated, such as secondary to heart disease, endocrine metabolic diseases, such as hypothyroidism, adrenocortical insufficiency, congenital heart disease, chronic metabolic diseases, such as the endocrine metabolic diseases, such as low blood pressure. Insufficiency, chronic congenital heart disease, and heart failure can all lead to chronic hypotension. Postural hypotension can also lead to the above conditions. Postural hypotension is often directly related to middle-aged and elderly people, especially those who have been taking antihypertensive drugs for a long time.