There are many reasons for always being sleepy and wanting to sleep, and the common causes are mainly the following: 1. Insufficient blood supply to the cerebral arteries. The disease is due to atherosclerosis caused by the decline in vascular elasticity, thickening of the vessel wall, resulting in relative narrowing of the blood vessels, blood flow is reduced, thus causing brain ischemia, hypoxia, drowsiness, weakness, dizziness and other symptoms, taking drugs to improve circulation can ease the symptoms; 2, depression. The disease will not only have symptoms of drowsiness and weakness, but also serious depression and self-harming tendencies, which require psychological intervention and psychological guidance through specialist doctors and auxiliary medication to effectively relieve the symptoms; 3, pharmacological factors, such as the use of certain drugs, such as sleeping pills, sedatives and anti-allergy drugs, can also appear drowsiness, mental lethargy and other symptoms, immediately stop using drugs, these symptoms can effectively relieve the symptoms.