Soreness on one side of the neck is related to long-term improper posture, trauma, and cervical spondylosis. Temporary observation, general treatment, medication, and surgery can be taken to relieve the symptoms according to the cause. 1. Improper posture: not paying attention to posture while sitting or lying down may cause neck muscles to be stretched for a long time, which is easy to cause soreness. This situation generally does not require special treatment, should adjust the habits, if the soreness is more obvious, can be appropriate hot compresses to relieve the symptoms. 2. Trauma: If only minor trauma, within 72 hours, you can choose to localized hot and cold compresses, 72 hours later, then switch to local hot compresses to eliminate swelling. If the trauma is more serious, you can consider doing microwave physiotherapy, infrared physiotherapy. 3. Cervical spondylosis: It is necessary to improve the bad habits in time, adjust the sitting posture, and insist on exercising the shoulder and neck muscles, so that the muscles relax. If the condition is more serious, oral non-steroidal anti-inflammatory drugs, such as celecoxib and etoricoxib, can be taken as prescribed by the doctor. More serious patients can consider surgical treatment, such as anterior surgery and posterior surgery. Before treating neck pain on one side, it is recommended to consult a doctor to understand the cause of the disease and avoid unauthorized use of medication.