Sleeping in the middle of the night arm numbness may be physiological factors, but also may be the manifestation of certain diseases, such as cervical spondylosis, vitamin B deficiency, diabetes, etc., should be timely consultation to identify the cause. 1. Physiological factors: it is possible to sleep in an improper posture, resulting in upper limb nerve compression, the symptoms of numbness of the limbs. 2. Pathological factors (1) cervical spondylosis, cervical disc herniation: cervical disc herniation is easy to compress the nerve root, if the posture is not suitable or the pillow is not suitable, it can aggravate the nerve compression, which can cause numbness of the arm, hand numbness. (2) Vitamin B deficiency: some patients with symptoms of arm numbness in the middle of the night, may be due to vitamin B deficiency, because vitamin B deficiency is easy to secondary neurasthenia, leading to numbness of the limbs of the patient, sleep disorders, low back pain symptoms. (3) diabetes: diabetes can also lead to the symptoms of numbness in the arm in the middle of the night, mainly because diabetes is easy to damage the peripheral nerves, triggered by diabetic peripheral neuropathy, which leads to numbness in the limbs of the patient’s symptoms. In addition to the above factors, it is not excluded that it is caused by other factors. It is recommended that if the physiological causes are excluded, the patient should consult the doctor in time, so that the doctor can clarify the cause of the disease and give targeted treatment.