Sleep apnea hypoventilation syndrome (SAHS), characterized by recurrent and frequent apnea and hypoventilation during sleep, can cause and/or exacerbate hypertension and is an important cause of refractory hypertension. The majority of patients with SAHS clinically belong to obstructive sleep apnea hypoventilation syndrome (OSAHS). The hypertension associated with OSAHS is called obstructive sleep apnea-associated hypertension, and is an independent risk factor for cardiovascular and cerebrovascular diseases. The prevalence of hypertension in our OSAHS population is 56.2%. Sleep apnea syndrome in adults includes: OSAHS (the most common clinical condition); central sleep apnea syndrome (CSAS); sleep hypoventilation syndrome, etc. Major risk factors (1) Obesity: body mass index (BMI) >28kg/m2 increases the prevalence of OSAHS by 10 times compared to that of OSAHS <24kg/m2. (2) Age: the prevalence increases with age; the number of women with OSAHS increases after menopause; (3) Gender: there are significantly more men than women with OSAHS during the reproductive years; (4) anatomical abnormalities of the upper airway: nasal obstruction (nasal septum deviation, turbinate hypertrophy, nasal polyps, nasal tumors, etc.), tonsillar hypertrophy of degree II or higher, soft palate relaxation, excessive length and thickness of the suspensory lobe, pharyngeal stenosis, pharyngeal tumors, pharyngeal mucosa hypertrophy, tongue hypertrophy. (5) family history of OSAHS; (6) long-term heavy alcohol consumption and/or sedative-hypnotic or muscle relaxant drugs; (7) long-term smoking; (8) other related diseases: including hypothyroidism, acromegaly, hypopituitarism, vocal cord paralysis, neuromuscular disorders (e.g. Parkinson's disease) ), long-term gastroesophageal reflux, etc. Clinical manifestations Nocturnal snoring, irregular snoring, disturbance of breathing and sleep rhythm, repeated apnea/awakening, or patients may feel breath-holding, increased nocturnal urination, morning headache, dry mouth, daytime sleepiness, memory loss, or psychological/intellectual/behavioral abnormalities in severe cases. May be combined with coronary artery disease, arrhythmia, stroke, type 2 diabetes and insulin resistance, progressive weight gain. Blood pressure characteristics (1) Elevated blood pressure at night and in the morning, elevated or normal blood pressure during the day: higher in the early morning when waking up than before bedtime. Some patients exhibit insidious hypertension. (2) Disturbed blood pressure rhythm: 24h ambulatory blood pressure monitoring shows that the blood pressure curve is "non-ascending" or even "anti-ascending". (3) The effect of drug-only hypotension is poor, and the control of blood pressure depends on the effective treatment of OSAHS. Continuous positive airway pressure (CPAP) ventilation therapy can reduce the use of antihypertensive drugs to a certain extent. (4) Periodic increase in blood pressure accompanied by apnea: Combined with ABPM and polysomnography (PSG) monitoring, it is seen that blood pressure exhibits recurrent episodes of transient elevation at night with the recurrent occurrence of apnea. (5) The high peak blood pressure occurs at the end of the apnea event, just after resumption of ventilation. Treatment Treatment for OSAHS: Very important Treatment for OSAHS, including: lifestyle, habit changes such as weight loss, postural therapy, smoking and alcohol cessation, and cautious use of sedative-hypnotics; non-invasive positive airway pressure ventilation therapy; surgical treatment and treatment such as oral appliances. Individualized treatment plan. Use sedative-hypnotics and other drugs that can cause or aggravate OSAHS, change the supine position to lateral sleep, etc. Non-invasive positive airway pressure ventilation treatment is the most certain. CPAP ventilation and bi-level continuous positive airway pressure ventilation are included. CPAP is most commonly used, and bi-level continuous positive airway pressure ventilation is recommended for those with significant CO2 retention. Oral orthodontic appliances: Suitable for patients with simple snoring and mild to moderate OSAHS, especially those with mandibular recession. Surgical treatment: surgical modalities include uvulopalatopharyngoplasty and modification, mandibular anterior migration and maxillofacial anterior migration with hyoid muscle cut-off suspension Anti-hypertensive drug treatment ①prefer ACEI or ARB,ACEI. the combination of valsartan, coxsartan and hydrochlorothiazide can effectively reduce the increase of blood pressure after apnea, and at the same time reduce the respiratory sleep disorder index, reduce vagal and sympathetic nerve tone. ② Calcium antagonists have some therapeutic effect but have no significant effect on blood pressure in REM. Unsuitable drugs: beta-blockers; colistin.