Secondary hypertension is more dangerous, secondary hypertension patients may die due to cerebral hemorrhage, aggravating the primary disease. 1. Cerebral hemorrhage: secondary hypertension is characterized by high blood pressure for a long period of time. Once the blood pressure of patients with secondary hypertension is not properly controlled, the cerebral arteries of the patients are prone to lesions, and the rupture of the small arteries after being damaged may easily lead to cerebral hemorrhage, bringing about cerebral hernia or death. 2. Aggravation of primary disease: secondary hypertension is mostly caused by renal disease, patients not only have secondary hypertension, but also have renal lesions or other diseases, which bring about renal parenchymal damage, resulting in renal failure. People who have hypertensive heart disease themselves will develop arrhythmia and heart failure when affected by secondary hypertension. It is because secondary hypertension is more dangerous, so when you find yourself suffering from this disease, you must go to a regular hospital in time.