The difference between primary and secondary hypertension is mainly in the cause of the disease, clinical manifestations, blood pressure level and the difficulty of treatment. 1. Pathogenesis: The cause of primary hypertension is not yet clear, and it is thought to be related to heredity, dietary habits, body weight, mental factors, etc. Secondary hypertension is often associated with renal disease, pheochromocytoma, primary aldosterone and other diseases. Secondary hypertension is often associated with renal disease, pheochromocytoma, primary aldosteronism and so on. 2. Clinical manifestations: Primary hypertension may present symptoms such as headache, dizziness, nausea, blurred vision, etc. Secondary hypertension may present symptoms such as headache, dizziness, nausea, and blurred vision. Secondary hypertension will show symptoms of primary disease, such as glomerulonephritis will show symptoms of hematuria, proteinuria, swelling and so on. 3. Blood pressure level: primary hypertension can be categorized into grade 1, grade 2 and grade 3 hypertension. Secondary hypertension is usually characterized by persistent hypertension. 4. Difficulty of treatment: Primary hypertension can be controlled with lifestyle interventions and medications. Secondary hypertension is difficult to control in the normal range if the primary disease is not actively treated. If you find abnormal blood pressure, please consult the hospital in time and treat it actively to avoid delaying your condition.