Once hypertension is diagnosed, there are many related tests to be performed. The purpose of the tests is to clarify whether hypertension is primary or secondary hypertension, to clarify the extent of damage to important organs such as heart, brain, kidney and fundus of the eye, and to clarify the next step in the selection of antihypertensive drugs. cardiac ultrasound, ambulatory electrocardiogram; 4, head CT, head MRI; 5, fundus-related examination. If secondary hypertension is to be identified, tests related to renin levels should also be performed to exclude secondary hypertension.