Low blood pressure may lead to headache. The main mechanism is that low blood pressure often leads to insufficient blood supply to the brain, which leads to ischemia and hypoxia of brain tissue, reduction of cerebrospinal fluid vascular volume, endocrine imbalance of the central nervous system, or imbalance of contraction and diastole of blood vessels, resulting in reduced tension and thus headache. In terms of treatment, we should clarify the cause of hypotension, whether it is due to insufficient blood volume, whether there are oral antihypertensive drugs, whether there are malnutritional diseases, and whether there are infectious immune diseases, and provide regular treatment after determining the cause. In addition to hypotension, other causes of headache should be excluded, such as cerebral infarction, cerebral hemorrhage and other cranial diseases, and cranial CT or cranial MRI can be performed. If the headache is caused by insufficient blood volume, the blood volume can be supplemented with appropriate rehydration, saline or balance solution.