The type of hypertension is determined by the primary cause; hypertension with a primary cause is secondary hypertension, and hypertension for which no cause can be found is primary hypertension. Hypertension for which no clear cause can be found is referred to as essential hypertension. The cause of primary hypertension is unknown, and it is believed that it may be related to factors such as genetics, dietary environment, and age, but there is no clear cause. When there is a clinical symptom of hypertension and a clear disease can be identified, it is called secondary hypertension. For example, hypertension caused by renal vascular disease, such as pheochromocytoma, and some endocrine diseases, such as primary aldosteronism, hyperthyroidism and other diseases caused by hypertension, this kind of disease-induced hypertension is called secondary hypertension. Primary hypertension can be distinguished from secondary hypertension by asking about family history, past history, physical examination, clinical manifestations, laboratory tests such as urine routine, blood biochemistry, thyroid hormone level, and imaging tests such as renal artery ultrasound, CT, and cardiac ultrasound. It is recommended to go to the hospital in time when you have high blood pressure, to clarify the cause of the disease and then symptomatic treatment, so as to avoid adverse consequences.