Dizziness and drowsiness are always wanting to sleep, considering that it may be physiological reasons, or it may be caused by cervical spondylosis, insufficient cerebral blood supply and other diseases. 1. Physiological reasons: when there is mental stress, overwork and other situations, resulting in insufficient sleep, may cause brain dysfunction, dizziness, drowsiness and other symptoms. It is recommended to have a reasonable work and rest, appropriate exercise, and avoid excessive mental stress. 2. Cervical spondylosis: When cervical spondylosis is more serious, it can easily lead to proliferative degeneration of the cervical vertebrae, compressing the vertebral basilar artery system, thus causing insufficient blood supply to the brain, resulting in dizziness, drowsiness and other symptoms. 3. Insufficient cerebral blood supply: when patients combined with intracranial and extracranial blood vessel stenosis or occlusion, the blood flow to the brain decreases, causing insufficient cerebral blood supply, feeling dizzy and wanting to sleep. Dizziness always want to sleep, there may be caused by other diseases, it is recommended to go to the hospital in a timely manner to identify the causes of targeted treatment.