After attention has been paid to improving lifestyle and applying adequate doses and reasonable 3 antihypertensive drugs (including diuretics), blood pressure is still above the target level, or at least 4 drugs are needed to bring blood pressure up to the standard, which is called intractable hypertension (or refractory hypertension), accounting for about 15-20% of hypertensive patients. 1, possible causes (1) pseudo-refractory hypertension: improper blood pressure measurement methods (such as incorrect posture when measuring, thicker upper arms did not use a larger cuff), simple office (white coat) hypertension, combined with home self-measurement blood pressure, ambulatory blood pressure monitoring can make blood pressure measurement results closer to the real. (2) Drug-related causes: poor patient compliance (not adhering to medication), inappropriate selection of antihypertensive drugs (low dose, combination of drugs not reasonable enough), and drugs in use to raise blood pressure (such as oral contraceptives, adrenal steroids, cocaine, licorice, ephedra, etc.). (3) Unchanged poor lifestyle or failed to change (weight gain or obesity, smoking, heavy alcohol consumption) (4) Volume overload (inadequate diuretic therapy, high salt intake, progressive renal insufficiency) (5) With chronic pain and chronic anxiety, etc. (6) If there is no cause after the above, secondary hypertension should be excluded. (2) Communicate with the patient to improve long-term medication compliance and strictly limit sodium intake; (3) Select an appropriate combination regimen, starting with a 3-drug regimen such as ACEI (or ARB) + CCB + thiazide diuretics, or a three-drug combination regimen consisting of vasodilators, heart rate reducers and diuretics, which can target (4) After failure of previous combination therapy, another treatment regimen can be restarted under close observation; (5) Primary hypertension cannot be cured and requires long-term or even lifelong treatment; (6) For (6) For the treatment of renal hypertension, the most effective antihypertensive drugs that protect the kidney, such as ACEI, ARB, CCB, α or β-blockers, diuretics, etc., should be used, and percutaneous renal balloon angioplasty and stenting can effectively treat renal artery stenosis. (8) Pheochromocytoma and adrenomedullary hyperplasia have increased plasma/urine catecholamines, and CT scans are useful in localizing the diagnosis. (9) ion channels in the smooth muscle cell membranes of resistance arteries and small arteries play an important role in the regulation of vascular tone, and ion channels are involved in the generation and regulation of vascular tone by controlling Ca2+ transport and membrane potential; therefore, CCB is the baseline drug for the treatment of intractable hypertension; (10) beta-blockers and non-dihydropyridine CCB are available for increased cardiac output; (11) ACEI, ARB, dihydropyridine CCB, hydrazidiazine should be used for high peripheral vascular resistance, and collaterals diuretics or thiazide diuretics should be used for increased plasma volume load. (12) Use α1-blockers and α1-blockers for increased plasma catecholamines, β-blockers, ACEI, ARB for increased plasma renin activity, spironolactone for increased plasma/urinary aldosterone; (12) Use α1-blockers for positive anti-α1-adrenoceptor antibodies, ARB is a reasonable choice for positive anti-AT1-receptor antibodies; (13) Provide health education to patients and urge (13) Patients should receive health education and be urged to develop weight reduction plans, eat properly, and follow good lifestyle habits.