Patients who squat for a long time and lie for a long time after standing up dizziness, should consider the following points: First, the most common factor is upright hypotension, also known as postural hypotension, is a kind of blood pressure regulation abnormal performance, especially in the middle-aged and elderly population is particularly common, patients in the case of lying for a long time or squatting for a long time, after standing up there will be dizziness, headache, a transient black cloud in front of the eyes, accompanied by syncope, discomfort. Secondly, if the patient has insufficient blood volume due to various factors, the above symptoms will also occur, such as dehydration caused by heavy sweating or acute gastroenteritis in the summer heat, or dehydration caused by heat stroke, these conditions will also cause the above symptoms. Third, adverse drug reactions, such as long-term use of vasodilators, diuretics, antihypertensive drugs, antidepressants will cause adverse reactions. Fourth, weakened endostatic regulation, for example, under long-term bed rest or chronic cardiac insufficiency, will also have this clinical manifestation.