Patients who suddenly stand up with blackness in front of their eyes after squatting usually belong to the manifestation of abnormal regulation of blood pressure, called upright hypotension, which is especially common in the elderly. Patients may experience dizziness, blackness, fainting, and other severe maladaptive reactions after standing up quickly. Causes of this condition: 1. non-neurogenic causes, such as the presence of insufficient blood volume in the patient, such as obvious dehydration, heat stroke, and other factors. 2. endocrine metabolic disorders, such as thyroid dysfunction, adrenal insufficiency. 3. adverse drug reactions, such as long-term use of vasodilators, diuretics, antihypertensives, or antidepressants. 4. impaired regulation of the internal environment. 5. in chronic cardiac dysfunction, acute pericarditis, etc. In cases of chronic cardiac insufficiency and acute pericarditis, the above conditions may also occur. 6, neurogenic etiology, such as acute cerebrovascular insufficiency, the above conditions may also occur.