Numbness of the left fingers may be caused by physiological factors, cervical spondylosis, upper extremity nerve compression, diabetes and other factors. 1. Physiological factors: prolonged compression of the fingers of the left hand or maintaining a position for too long may lead to blood circulation, which will cause numbness of the fingers, no other clinical symptoms, reasonable activities can be recovered on their own. 2. Cervical spondylosis: prolonged excessive bowing of the head may cause cervical spondylosis, resulting in upper extremity nerves are compressed, it is easy to cause numbness of the left fingers, accompanied by neck and shoulder pain, upper extremity radiating pain, numbness of the upper extremities and other symptoms. 3. Upper extremity nerve compression: median nerve or ulnar nerve compression, it is easy to lead to the left hand finger numbness, the common disease for carpal tunnel syndrome or elbow tube syndrome, may also be accompanied by radiating pain, can lead to activity dysfunction in severe cases. 4. Diabetes: diabetes for a long time, may induce peripheral neuropathy, will lead to numbness of the limbs and sensory abnormalities, manifested as numbness of the left hand fingers and sensory loss. Left finger numbness, and accompanied by other abnormalities, should be alert to disease factors, it is recommended to seek medical treatment for appropriate examination and treatment, to avoid delaying the condition.