Cervical vertebrae 3/4/5 protrude backward, and according to the nerves compressed by 3/4/5, they do not cause hand numbness. Numbness of the hand may be caused by compression of the cervical 6, 7 and 8 nerves. 1. Cervical 3∽4 disc herniation will compress the cervical 4 nerve, which mainly manifests as pain and numbness in the back of the neck and radiates to the anterior chest. There is no hypotonia or tendon reflex changes. 2. Cervical 4-5 disc herniation will compress the cervical 5 nerve, mainly manifested as radiating along one side of the neck and shoulder, numbness at the deltoid muscle, deltoid muscle weakness and atrophy, no reflex changes. 3. Cervical 5∽6 disc herniation will compress the cervical 6 nerve, mainly manifested as pain and numbness radiating along the lateral side of the upper arm and forearm to the thumb and index finger. Biceps muscle strength and reflexes are diminished. 4. Cervical 6∽7 disc herniation will compress cervical 7, which will have pain and numbness radiating distally along the dorsal center of the upper arm and forearm to the middle finger, and may also involve the index finger and ring finger. 5. If the cervical 8 nerve is compressed, there will be sensory loss in the ring finger, little finger and ulnar side of the palm. With different planes of cervical spondylosis, there will be differences in the compression of nerves, which will result in different clinical symptoms. CT and MRI can be used to understand the plane of herniation and nerve compression. If you feel numbness and discomfort in your hands, in order to avoid aggravation of the condition, it is recommended to consult a doctor in a timely manner, under the guidance of a professional doctor, to understand the specific development of the condition through auxiliary examinations, and to take timely therapeutic measures.