Refractory hypertension is a difficult problem in the treatment of hypertension. Refractory hypertension is called refractory hypertension when blood pressure is not achieved after applying a reasonably tolerable adequate dose of ≥3 antihypertensive drugs (including diuretics) for >1 month on the basis of lifestyle improvement, or when blood pressure can be effectively controlled only after taking ≥4 antihypertensive drugs. With reference to the results of clinical trials in recent years, combined with data from patients with frequently seen hypertension and available data from hypertension research centers, it is projected that patients with refractory hypertension account for 5% to 30% of patients with hypertension. There are many factors that influence the difficulty in achieving blood pressure targets, including poor patient lifestyle, poor patient compliance, inadequate or irregular drug therapy, and secondary hypertension. The causes of poor blood pressure control should first be identified to exclude pseudo-refractory hypertension. ①Incorrect blood pressure measurement is a common cause of pseudo-refractory hypertension; ②Treatment compliance: analyze whether the patient continues to take medication as prescribed; ③Whether the patient is taking medications that affect blood pressure “such as licorice, non-steroidal anti-inflammatory drugs, oral contraceptives, steroids, cyclosporine, erythropoietin, ephedrine, etc.; ④Lifestyle factors: whether there is high salt intake, excessive anxiety, heavy smoking, heavy obesity, chronic pain, etc. chronic pain, etc.; ⑤ the presence of inadequate medication for hypertension: such as insufficient drug dosage or failure to use diuretics or incorrect combination regimen; ⑥ looking for clues of secondary hypertension. In recent years, with the improved understanding of the etiology of hypertension and improved clinical diagnostic techniques, the detection rate of secondary hypertension has increased significantly. Secondary hypertension often has the clinical characteristics of high blood pressure level, multiple antihypertensive drugs combined with the treatment of blood pressure is still difficult to control as well as through the treatment of the cause of the disease can be significantly controlled or even return to normal blood pressure. Therefore, identifying secondary hypertension and treating it accordingly is one of the key aspects of controlling refractory hypertension. All refractory hypertension should be alerted to the possibility of secondary hypertension, and attention needs to be paid to screening for secondary hypertension from history, symptoms, signs, and routine laboratory tests.