The diagnosis of primary hypertension is usually secondary hypertension and other secondary causes of hypertension: 1. Kidney disease, such as chronic glomerulonephritis, acute glomerulonephritis, chronic pyelonephritis, nephrotic syndrome can lead to secondary hypertension and varying degrees of swelling. 2. Endocrine metabolic diseases can also lead to increased blood pressure, such as adrenal pheochromocytoma, aldosteronism. 3. The blood pressure can also be increased by endocrine metabolic diseases, such as adrenal pheochromocytoma and aldosteronism. 3, cardiovascular pathologies need to be differentiated from primary hypertension, such as aortic valve insufficiency and aortic constriction, etc. 4, cerebrovascular diseases, such as brain tumors, brain displacements and traumatic brain injury, etc. 5, other infectious diseases can also have a transient increase in blood pressure, and need to be differentially diagnosed from primary hypertension.