Our hypertension is divided into primary hypertension and secondary hypertension, it is actually diagnosed by the same criteria, greater than 140/90mmHg, we can be diagnosed as hypertensive disease. The difference between primary hypertension and secondary hypertension is: first, the age of onset. The age of onset of primary hypertension is relatively large, usually the middle-aged and elderly, while patients with secondary hypertension tend to have a younger age of onset, usually less than 30 years old. Second, primary hypertension is no clear cause, that is, the current medical situation can not find a clear cause, while secondary hypertension is that we can find a clear cause, is to find a specific disease caused by the rise in blood pressure, which is called secondary hypertension. Third, primary hypertension is relatively easy to control, while secondary hypertension is less easy to control without removing the cause. So when a person’s blood pressure is very difficult to control, especially in younger patients, we must rule out the presence of secondary hypertension.