Stroke has become the second leading cause of death and a major long-term disability in the world, putting tremendous pressure on society’s medical resources. Despite the many measures taken to control hypertension, lipids, blood glucose, smoking cessation, and treatment of atrial fibrillation, it remains a high public health concern. For stroke patients, i.e. those who have suffered from cerebrovascular diseases such as cerebral infarction, cerebral hemorrhage, TIA, etc., while paying attention to your risk factors such as blood pressure, blood lipid, blood sugar, etc., please pay attention to your sleep problems, whether you snore at night, whether you snore loudly, whether you have a continuous snoring in which the snoring suddenly stops for a few seconds, whether you wake up at night and sit up? Once you have bad sleep at night, you will have no energy during the day, always doze off and a series of other problems. Of course, you don’t know this during sleep, and you need to ask the person next to you (including the person who sleeps with you). If you have these sleep abnormalities, you may have what is known medically as obstructive sleep apnea syndrome (OSAS). So is OSAS present, mild or severe? A small portable device, the size of a cell phone, will record both apnea and hypoventilation determined by nasal airflow during nighttime sleep, as well as oxygen saturation measured by an oximeter. Because it is a small portable device, you don’t have to sleep in the hospital to monitor it, just take it home and bring it back with you the next day to know how you slept overnight, such as the number of snores, apnea, hypoventilation, nighttime oxygen saturation, etc. Sleep is an important physiological activity, and during normal sleep, the heart, lungs and cerebrovascular vessels are regulated differently by different sleep times. In OSAS patients, repeated pharyngeal airway collapse occurs during sleep and ends when they wake up and sit up. The decrease or cessation of airflow creates hypoxemia and hypercapnia and the resulting series of secondary damages; while chemical stimulation due to elevated hypoxia and carbon dioxide or mechanical stimulation due to increased respiratory effort can produce respiratory wakefulness, causing disintegration of sleep structures, sleep interruption, sleep deprivation and the resulting series of psychiatric, neurological and endocrine changes. The alternation of apnea and sleep disruption is an important feature of OSAS. Due to sympathetic nervous system activation, arterial blood pressure can fluctuate at night and often rises to high levels in OSAS patients. Patients with severe OSAS are at increased risk of accidents and their quality of life can be compromised. For patients who present with nocturnal hypertension alone, be concerned if you have sleep apnea. There has been increasing evidence in recent years that OSAS is associated with cerebrovascular disease or neuropathy. Several studies have shown that the prevalence of OSAS can be as high as 60% in stroke patients, compared to only 4% in the same group of middle-aged adults. The data provide ample evidence that OSAS is an independent risk factor for stroke, and concern has been raised about the mutual effects of OSAS and stroke. Why OSAS has consequences of cerebrovascular damage involves neurological, humoral, vascular and inflammatory abnormalities. It has been found that those with OSAS complicated by stroke are older, more male, and more likely to have OSAS than those with OSAS complicated by cardiovascular disease, especially in obese patients. OSAS is one of the risk factors for stroke that can be intervened, so if your sleep is similar, pay early attention to sleep apnea monitoring.