Left hand and left foot numbness, may be related to mechanical compression, may also be due to cervical spondylosis, acute cerebrovascular disease and other reasons. 1. Mechanical compression: commonly seen in sleeping, if you keep lying on your side for a long time, resulting in the left hand and left foot long time pressure, resulting in the pressure part of the blood circulation is not good, will cause the left hand and left foot numbness, and is not accompanied by other discomforts, when the posture is changed, after appropriate activities, the symptom can be disappeared very quickly. 2. Cervical spondylosis: especially the existence of cervical disc herniation patients, in the sleep due to long time to maintain an improper sleeping posture, resulting in local nerve root compression, may cause left hand and foot numbness, but also can be accompanied by numbness of the upper limbs, weakness, neck and shoulder discomfort and other symptoms. 3. Acute cerebrovascular disease: commonly seen in acute cerebral hemorrhage or cerebral infarction, due to local cerebral hemorrhage or ischemia, resulting in cerebral nerve damage, causing cerebral dysfunction, there may be a numbness of the left hand and left foot of the neurological deficits, but also accompanied by dizziness, headache and other manifestations. If the symptoms of numbness in the left hand and foot persist and cannot be relieved, attention should be paid and medical treatment should be sought as soon as possible to diagnose the cause and then give targeted treatment by perfecting the relevant examinations.