If the patient is dizzy when standing up while lying down, accompanied by blackness in front of the eyes, the following causes should be considered: First, the most common factor is upright hypotension, also known as postural hypotension, which is a manifestation of abnormal blood pressure regulation and is especially common in the elderly population, and the patient will experience clinical symptoms and manifestations of dizziness, transient blackness in front of the eyes, and syncopal discomfort after standing up quickly. Second, if the patient has insufficient blood volume due to various factors, such as summer heat stroke or acute gastroenteritis, nausea, vomiting, excessive number of diarrhea, or bleeding or trauma caused by various factors, which triggers insufficient blood volume, he will also have this symptom. Third, the side effects and adverse reactions of taking certain drugs, such as taking vasodilators, diuretics, antihypertensives and antidepressants after long-term treatment. Fourth, the endostatic regulation function is weakened, for example, the patient is bedridden for a long time in the elderly, or there is chronic cardiac insufficiency, at this time, there will also be this clinical symptoms and performance.