Some patients will blindly purchase their own medication or go to the hospital to have their doctor prescribe antihypertensive medication to take when they find elevated blood pressure, which is a very irresponsible practice for them. The purpose of the examination is to find the cause of hypertension (primary or secondary) on the one hand, and to assess the functional status of the patient’s target organs and to gain a comprehensive understanding of the patient’s physical condition to guide the physician in formulating a reasonable treatment plan. The examination is divided into the following two aspects: physical examination and laboratory tests. The whole body physical examination is very important. In addition to measuring blood pressure carefully according to the correct method (blood pressure should be measured bilaterally when measuring blood pressure for the first time, and the blood pressure of both lower limbs should be measured at the same time if possible), it should include the following: measuring height and weight; measuring waist circumference and abdominal circumference; paying attention to heart size, heart sound, heart rate, heart rhythm and the presence of murmurs; paying attention to the presence of rales and bronchospasm in the lungs; paying attention to the presence of blood vessels in the neck and large blood vessels in the lower limbs. The abnormalities and murmurs of blood vessels in the neck and lower extremities or the enlargement of the thyroid gland; the murmurs and masses of blood vessels in the abdomen; and the abnormal changes of the fundus of the eyes and the nervous system. Routine laboratory tests include complete blood count; urine routine; blood sodium, potassium, calcium; plasma urea nitrogen, creatinine, uric acid, fasting glucose; lipid analysis; electrocardiogram; cardiac ultrasound, neck vascular ultrasound, pulse wave conduction velocity, and ambulatory blood pressure. In addition, the following tests should be selected based on history, physical examination and routine laboratory findings, or if secondary hypertension or target organ damage is suspected with significantly elevated blood pressure: plasma renin activity, plasma aldosterone, plasma free 3-methoxyadrenaline, plasma free 3-methoxynorepinephrine, plasma cortisol, blood and urine catecholamines, urine 17-hydroxyl and 17-ketone measurements, chest X-ray, adrenal urography, renal arteriography, etc. When the doctor has a thorough understanding of the condition and sees the patient’s test results, he or she can select the right antihypertensive drug for the patient’s individual situation.