Pain on one side of the neck may be due to the following reasons: First, postural reasons: Keeping a bad posture for a long time, such as tilting the head to study or work, will easily lead to continuous strain on one side of the neck muscles, thus causing clinical symptoms of pain on one side of the neck, usually soreness and swelling. After moving the neck or massaging the neck, the symptoms will disappear completely. Second, cervical spondylosis: the cervical intervertebral disc protrudes to one side and compresses the nerve root, which can cause the continuous spasm and tension of the neck muscles on that side, accompanied by the clinical symptoms of neck pain, and the range of cervical spine activities will also be limited, and the cervical intervertebral disc protrusion will be detected by CT scanning or magnetic resonance imaging (MRI). Early diagnosis and treatment can lead to satisfactory relief of the above clinical symptoms. If treatment is delayed, the condition will continue to aggravate and eventually compress the nerves, causing limb dysfunction.