There are many causes of high low pressure, such as infectious diseases, anemia, diabetes, kidney disease, cardiovascular disease, etc., all of which can affect the fluctuation of low pressure. High low pressure usually requires examination of blood routine, urine sugar or blood glucose, urinalysis or renal function, 24-hour ambulatory blood pressure, echocardiography, electrocardiogram, etc. 1. Routine blood test: Routine blood test can indicate the presence of infectious diseases and anemia leading to elevated low pressure. 2. Urine sugar or blood glucose: urine sugar or blood glucose test can be used to make a preliminary diagnosis of diabetes mellitus. 3. Urine routine or renal function: according to urine routine or renal function can initially determine whether there is kidney disease. 4. 24-hour ambulatory blood pressure: It can dynamically monitor the changes of blood pressure within 24 hours to assess the situation of high low pressure and facilitate the diagnosis of hypertension, etc. 5. Echocardiography: It can understand the structure of the heart and blood flow, and determine whether there is a heart disease that causes high low pressure. 6. Electrocardiogram (ECG): It can determine whether there is any abnormality in the function and structure of the heart, leading to high low pressure. When you have high low pressure, you should go to a regular hospital in time to clarify the cause and diagnosis, and standardize the treatment under the guidance of physicians to avoid delaying the condition.