The causes of dizziness in hypotension are primary hypotension and secondary hypotension. Upright hypotension can also have a transient low blood pressure, which is not necessarily the cause of the disease. 1. Primary hypotension: primary hypotension is a kind of unexplained low blood pressure, mostly seen in young, frail women. 2. Upright hypotension: Suddenly going from sitting or squatting position to standing position will cause transient hypotension, resulting in dizziness and blackouts. After a few minutes, it will get better on its own and is not caused by disease. 2. Secondary hypotension: The common causes of secondary hypotension are insufficient blood volume, infection, allergy, anemia, heart attack, etc. In addition to the symptoms of dizziness of low blood pressure, the symptoms of primary diseases are more prominent. Long-term low blood pressure should be promptly consulted and treated according to medical advice to avoid adverse consequences.