Hypertension is a common and frequent disease at present, and some patients who have taken three antihypertensive drugs still cannot effectively lower their blood pressure and consult their doctors. Clinically, we mostly call hypertension that cannot be controlled despite taking three or more antihypertensive drugs (including diuretics) refractory hypertension, which will be elaborated in this article with the latest international and domestic guidelines. I. Definition of refractory hypertension Refractory hypertension is defined as: Definition of refractory hypertension: after at least 4 weeks of treatment with tolerable and adequate doses of three antihypertensive drugs (usually including long-acting calcium channel blockers, renin-angiotensin system inhibitors, prilosec or sartans, and diuretics) based on lifestyle improvement, in-office and out-of-office (including home blood pressure or ambulatory blood pressure monitoring) When the blood pressure value is still above the target level or when at least 4 drugs are required to bring the blood pressure to the target, it is called refractory hypertension. Second, the possible causes of refractory hypertension Determining whether a patient is RH often requires the use of out-of-office blood pressure measurement (home blood pressure measurement and ambulatory blood pressure monitoring) in conjunction to exclude white coat hypertensive effects as well as pseudohypertension. To find the causes of poor blood pressure control and coexisting disease factors: 1, the more common cause is poor compliance with treatment, the patient can not take oral antihypertensive drugs on time and in the right amount; 2, antihypertensive drug selection and use of inappropriate (drug combination is unreasonable, the use of drug dose is insufficient); 3, the application of antagonistic antihypertensive drugs, including oral contraceptives, cyclosporine, erythropoietin, glucocorticoids, nonsteroidal anti-inflammatory drugs, antidepressants, cocaine, and certain Chinese herbs (e.g., licorice, ephedra); 4, other influencing factors are: poor lifestyle (high salt diet), obesity, volume overload (inadequate diuretic therapy, progressive renal insufficiency); or certain coexisting disease conditions, such as diabetes, dyslipidemia, chronic pain and chronic insomnia, anxiety, etc.; 5, after excluding the above factors, one should be alert to the possibility of secondary possibility of hypertension and initiate screening for secondary hypertension. First, patients should be referred to a physician specializing in hypertension. The diagnosis of refractory hypertension should be determined by a qualified hypertension specialist. Advocate for out-of-office blood pressure measurement (home blood pressure and ambulatory blood pressure) and effective communication with the patient. Focus on the patient’s long-term medication adherence. Second, try to eliminate influencing factors. The main ones are obesity, metabolic disorders, excessive sodium intake and other poor lifestyle habits. Again, adjust the antihypertensive combination scheme. Firstly, check whether the composition of the multi-drug combination program is reasonable. It is recommended to choose the regular dose of the priligy or sartan, diphenhydramine and thiazide diuretics, and also consider increasing the dose of each drug according to the patient’s characteristics and tolerance. In addition, a fourth antihypertensive drug can be added according to the patient’s characteristics if the effect is still unsatisfactory. The choice can be made between an aldosterone receptor antagonist, a beta-blocker, an alpha-blocker or a sympathomimetic depressant (colistin), but the principle of individualized treatment still needs to be applied. Finally, denervation nerve surgery (RDN) is an emerging technique, seeing that there is still insufficient evidence regarding the efficacy and safety of RDN for RH, so this method is still in the clinical research stage and is not suitable for widespread clinical dissemination. In conclusion, the diagnosis and treatment of refractory hypertension are relatively complex, and if blood pressure cannot be effectively controlled with regular treatment with three drugs, one should consult a hypertension specialist for regular treatment, and should not let it develop.