Grade 3 hypertension refers to systolic blood pressure >180mmHg and/or diastolic blood pressure >110mmHg; while sleep apnea syndrome, also known as obstructive sleep apnea hypopnea syndrome, is characterized by sleep snoring with recurrent apnea; and may eventually lead to cardiovascular and cerebrovascular accidents, cognitive disorders, and even sudden death if no treatment measures are taken. 1. Cardiovascular and cerebrovascular accidents: These include sudden diseases of the heart and brain, such as myocardial infarction or cerebral infarction, cerebral hemorrhage and so on. 2. Cognitive impairment: because patients will have nighttime cerebral hypoxia, and long-term uncontrolled conditions, cognitive impairment is likely to occur. 3. Sudden death: Sudden increase in blood pressure or sudden cardiovascular and cerebrovascular accidents may lead to sudden death. Patients with grade 3 hypertension with sleep apnea syndrome should go to the hospital in time and be treated under doctor’s guidance to avoid jeopardizing personal life.