To check the cause of hypertension, tests are needed: 1. Check electrocardiogram and cardiac ultrasound to clarify the heart condition. 2. Urine routine, kidney function and renal ultrasound to rule out nephrogenic hypertension, especially to rule out adrenal pheochromocytoma, and renal artery angiography if necessary to clarify the presence of renal artery stenosis. 3. Check the six items of hypertension to rule out secondary hypertension due to endocrine factors. Other tests, including liver function, lipid and blood glucose measurements, are also helpful in the diagnosis of hypertensive patients.4. Genetic factors, obesity, over-salty diet, and stressful exertion can all lead to elevated blood pressure. If none of the above tests are abnormal, primary hypertension is considered a high possibility.