Dizziness from sleeping on the left side is mainly considered to be related to cervical spondylosis, otoliths and other causes. Patients should go to the hospital neurology or orthopedics department for cervical spine CT or nuclear magnetic examination to confirm the diagnosis.1. Cervical spondylosis: Due to long-term ambulatory work, long time playing with cell phone, wrong sleeping posture, etc., the patient’s cervical spine is deformed and the blood vessels in the spinal canal are compressed, resulting in insufficient blood supply to the brain. At this time, the patient maintains a long sleep posture on the left side, and symptoms such as dizziness and nausea can occur due to insufficient blood supply to the brain. Massage, acupuncture, massage and other methods can be used to relieve the symptoms, but if the condition is serious, surgery is required. Patients should exercise moderately in daily life and stretch the shoulder and neck muscles to relieve the discomfort symptoms. 2. Otolithosis: As the otolith particles in the patient’s ear fall off, when the position changes and the patient turns over towards the left side, the otolith stimulates the cell membrane of the semicircular canal, causing the patient to experience dizziness symptoms. At this time, drugs such as isoprostanes and betahistine can be taken under the guidance of a doctor to improve the microcirculation in the inner ear and to reset the otolith if necessary. Since otoliths are prone to recurrence, patients should maintain an optimistic and upward mood to promote recovery from the disease.