Nowadays, we often hear patients complain about the excessive and costly tests prescribed by their doctors, and other reasons are not discussed here. However, in addition to a comprehensive physical examination of hypertensive patients, some ancillary examinations must be done for the purpose of determining the cause of secondary hypertension, in addition to determining the damage caused by hypertension to target organs and the extent of that damage, in order to guide diagnosis, treatment, medication and judgment of prognosis. Auxiliary examinations are generally divided into routine and special examinations. (1) Routine tests include: urine routine, blood electrolyte measurement, kidney function, uric acid, blood lipids, blood glucose, and electrocardiogram, chest X-ray, etc. (2) Special examinations include: ultrasound, CT, MRI, echocardiography, renin-angiotensin-aldosterone measurement, etc. These examinations are all purposeful examinations. In other words, certain special tests are done only when primary diseases that can cause secondary hypertension are found or suspected after the consultation, physical examination and routine examination. As an example: if pheochromocytoma is suspected, ultrasound, CT, MRI, and morphological diagnosis can be done, which is more valuable for diagnosis. (3) Fundus examination is frequently performed. This is because the retinal arteries and veins are the only blood vessels in the body that can be directly observed in vivo, and examination of the fundus is one of the important tests for diagnosing hypertension, judging the condition and estimating the prognosis. When the retinal arteries have been significantly sclerotic, especially when combined with optic nerve papillary edema, it often indicates that other important organs in the body, such as the heart, brain, kidneys and other important organs may have been damaged to varying degrees. Almost all hypertensive patients with normal fundus have normal heart and good kidney function.