There are many reasons for the numbness of the left thumb, usually can often feel uncomfortable, found that the hand numbness, foot numbness, etc., numbness of the thumb is just one of them, the reasons are as follows: 1, the nerve is compressed by external forces: if the time is relatively short can be recovered very quickly; 2, cervical spondylosis of the compression: numbness or numbness of the thumb or a few fingers, or the whole finger is numb, you need to carry out a cervical spine examination. After the cervical spondylosis compression of the nerve, there can be a single finger numbness, there can also be several finger numbness; 3, diabetic peripheral nerve damage: there are a lot of diabetic patients have peripheral nerve damage, after the damage to the phenomenon of finger numbness, you need to check whether you suffer from diabetes; 4, nerve damage: due to trauma or external pressure caused by nerve damage can cause numbness of the fingers, not simply the thumb! Numbness; 5, fatigue, rest is not good: can also cause numbness of the finger phenomenon. Therefore, the phenomenon of numbness of the fingers, should be promptly to the hospital to avoid delay.