Numbness of the left little finger can be seen in peripheral neuropathy, the patient’s little finger contact with toxic substances or the patient has diabetes, alcoholism and so on, leading to vitamin B deficiency, peripheral nerve demyelination changes, the patient can appear in the numbness of the left little finger, and in severe cases, it can be accompanied by tingling, if necessary, you can check the electromyography. Treatment is mainly to give the patient supplement B vitamins, such as methylcobalamin, vitamin B12, can also give the patient oral vitamin B1, and at the same time to actively treat the primary disease. Numbness of the left little finger may also be caused by ulnar neuropathy, which may be caused by cervical spondylosis leading to ulnar nerve compression, or may be caused by elbow canal syndrome leading to ulnar nerve damage, the patient may have numbness of the left little finger, which can be confirmed by electromyography as well as corresponding elbow joint and cervical spine examination.