When blood pressure is high in young people, it is important to consider whether it is secondary hypertension. Secondary hypertension is a disease of the heart or other systems of the body that causes a secondary increase in blood pressure, which can be controlled and cured by improving other diseases later. The specific causes of secondary hypertension are divided into the following areas: 1. kidney malfunction, such as previous nephritis, and systemic lupus erythematosus or diabetes mellitus has an impact on the kidneys. Diabetic nephropathy, systemic lupus erythematosus kidney, and polycystic kidney may cause high blood pressure. The kidney also needs blood supply, and renal artery stenosis can cause problems in the regulatory system of blood pressure, i.e., imbalance in the regulation of the renin-angiotensin system can also cause elevated blood pressure. 2. Endocrine causes such as proaldosterone, i.e., primary aldosteronism, can manifest as high blood pressure and low blood potassium. There is also pheochromocytoma mainly manifested as high and low blood pressure; 3, some drugs can also cause blood pressure problems, such as long-term use of licorice tablets may cause secondary blood pressure; 4, genetic diseases, to be determined by genetic testing, such as the professional term called Liddle syndrome, can also cause secondary blood pressure, the disease is mainly for secondary factors treatment, blood pressure will be better improved.