The main causes of dizziness in low blood pressure are postural hypotension, primary hypotension, secondary hypotension, etc. You can choose to lie down, replenish blood volume, intravenous infusion, use drugs and other methods. 1. Postural hypotension: transient insufficiency of cerebral blood supply due to sudden standing up from lying or squatting position, resulting in transient dizziness and blackout. Generally, it can be relieved by itself in a short period of time. For serious cases, it is possible to lie down flat and relatively increase the cerebral blood flow to improve the symptoms. 2. Primary hypotension: Primary hypotension refers to low blood pressure of unknown cause. It is mostly seen in frail women. They should strengthen physical exercise and drink more water to increase blood volume. 3. Secondary hypotension: It is commonly caused by excessive bleeding, severe dehydration, infection or allergy. In addition, overdose of antihypertensive drugs, certain heart diseases, endocrine diseases, may also lead to. At this time, we should actively treat the primary disease, replenish blood volume, anti-infection, etc., and use dopamine and other antihypertensive drugs if necessary. Drugs should be used under the guidance of a physician, and combined diseases should be actively treated for primary diseases.