Arm pain at night and numbness during the day may be caused by poor sleeping posture, may also be due to cervical spondylosis, transient ischemic attack and other pathological factors, if the symptoms continue to be unrelieved, it is recommended to seek medical treatment in a timely manner. 1. Bad sleeping posture: if the patient likes to sleep on his side and put his arm under his body, the prolonged pressure will easily cause poor blood circulation in the arm, which will easily cause local spasm and numbness, etc. Usually, the symptoms can be relieved by changing the sleeping posture. 2. Cervical spondylosis: If you are a patient with cervical spondylosis, the cold stimulation at night as well as improper sleeping posture can aggravate the cervical spondylosis, which can cause the numbness of the arm to worsen when sleeping and normal during the day. 3. Transient ischemic attack: If the patient himself has a narrow blood vessel, the blood flow rate at night is relatively slow, easy to transient ischemia in the narrow blood vessel, which in turn shows dizziness and numbness of the upper limbs and other symptoms. Cause arm pain at night numb daytime normal causes more, if the patient accompanied by other symptoms of discomfort, should be timely to the hospital for examination, by the doctor for targeted treatment.