Numbness in the little finger and ring finger of the left hand while sleeping can first be considered as a result of cervical spondylosis. Generally, it is common that the herniated or pointed discs of 5, 6, and 7 of the cervical spine cause the nerve roots to be compressed, and the patient can experience numbness of the little finger and ring finger of the left hand. In severe cases, the patient may also experience weakness of the left hand. For this kind of numbness caused by cervical spondylosis, patients are advised to pay attention to the protection of the cervical spine and, if necessary, to consult an orthopedic surgeon for symptomatic treatment such as traction, acupuncture and massage. Among them, this type of cervical spondylosis is also called nerve root type cervical spondylosis. Secondly, numbness of the little finger and ring finger of the left hand during sleep can also be seen as a symptom of local compression. Clinically, it is more common that the ulnar nerve is compressed, especially due to carpal tunnel syndrome, and the patient can experience numbness of the little finger and ring finger of the left hand, and if necessary, electromyography can be checked.