Currently, commonly used antihypertensive drugs can be categorized into 5 major groups, namely diuretics, beta receptor antagonists, calcium channel blockers (CCB), angiotensin converting enzyme inhibitors (ACEI), angiotensin II receptor antagonists (ARB),. The side effects of different classes of drugs are different. 1, diuretics: there are three categories of thiazides (hydrochlorothiazide), tab diuretics (furosemide), and potassium-protective diuretics (spironolactone). The main adverse effects of thiazide diuretics are hypokalemia and affect the metabolism of blood lipids, blood sugar and blood uric acid, which often occur at high doses, so small doses are recommended, and others include weakness, increased urine output, and are prohibited in patients with gout. Potassium-protective diuretics can cause hyperkalemia, should not be used in combination with ACEI and ARB, and should be used with caution in renal insufficiency. 2, β receptor antagonists: there are selective (β1), non-selective (β1 and β2), and both α receptor antagonism three categories, the representative drugs are metoprolol, propranolol, carvedilol. β receptor antagonists on myocardial contractility, sinus node and atrioventricular node function have inhibitory effects, and can increase airway resistance. Adverse effects include bradycardia, weakness, and chills in the extremities. Acute heart failure, pathological sinus node syndrome, atrioventricular block patients are prohibited. 3, calcium channel blockers: divided into dihydropyridines (nifedipine) and non-dihydropyridines (verapamil and diltiazem). The main adverse effects are reflex sympathetic activity enhancement at the beginning of treatment, causing increased heart rate, facial flushing, headache, lower limb edema, etc., especially when using short-acting preparations. Non-dihydropyridines inhibit myocardial contraction and conduction function, and are often used to treat supraventricular tachycardia, and should not be used in patients with heart failure, sinus node hypofunction or heart block. 4, angiotensin converting enzyme inhibitors: adverse effects are mainly irritating dry cough and angioedema. Dry cough may be related to the increase of bradykinin in the body, and disappears after stopping the drug. Hyperkalemia, pregnant women and patients with bilateral renal artery stenosis are contraindicated. Use with caution in patients with blood creatinine above 3mg/dl. 5, angiotensin II receptor antagonists: treatment contraindications and ACEI the same, but generally does not cause irritating dry cough, less side effects, patients take the drug after good tolerance. In addition to the above five major antihypertensive drugs, there are some other antihypertensive drugs, such as sympathetic nerve inhibitors (reserpine), direct vasodilators (hydrazidiazide), and α1 receptor antagonists (prazosin), but because of more side effects, they are currently not advocated for use alone and can be combined with other drugs. Antihypertensive drugs should follow the principle of individualization. Patients need to make a reasonable drug regimen according to their specific conditions under the guidance of doctors.