Some male friends will encounter numbness in the left hand in their lives, sometimes disappearing in a short time, this situation is caused by the compression of peripheral nerves, is normal, no need to worry. But if there is a long time numbness situation, should pay attention to, this may be the motor nerve damage and cervical spondylosis caused. 1, peripheral neuritis or compression: the incorrect sleeping posture of men in life or the wrong position of the arm, which makes the peripheral nerve of the arm is seriously compressed, which leads to insufficient blood supply to the arm caused by the symptoms of numbness. 2, damage to the motor nerve: some male friends in the exercise of excessive or incorrect posture, resulting in some damage to the motor nerve, causing the arm numbness. So male friends in doing sports must be measured. 3, cervical spondylosis: men are more inattentive than women in life habits, so more men suffer from cervical spondylosis, the condition is also more serious. Cervical spondylosis not only compresses the nerve of the arm leading to numbness symptoms will also cause other diseases. Therefore, the causes of numbness in the left hand of men, the common main three points above, generally can be relieved by the shoulder and neck and finger movement, if it is a pathological cause, we must go to the hospital for examination, for treatment.