Possible causes of pain on the right side of the neck include cervical spondylosis, cervical lymphadenitis, subacute thyroiditis, cervical spine tumor, trauma, neck strain, etc. 1. Cervical spondylosis: cervical spondylosis is a type of disease secondary to cervical spine degeneration, in which neurogenic cervical spondylosis is mainly manifested as neuroradiation pain in the neck, shoulder or upper limb. When cervical degeneration compresses the corresponding nerve roots on the right side, it can cause right-sided neck pain. 2. Right-sided cervical lymphadenitis: cervical lymphadenitis is mostly caused by the spread of infected foci in neighboring tissues, such as tonsillitis, gingivitis, pharyngitis, etc. Patients will have localized lymph node swelling. Patients will have localized lymph node enlargement, pain, severe lymph nodes can be fused with each other, surface skin redness and fever. 3. Subacute thyroiditis: Subacute thyroiditis is often secondary to viral infections, followed by enlargement of the thyroid gland and neck pain, mostly from one side of the thyroid gland. 4. Cervical spine tumor: when cervical spine tumor compresses the nerve root at the back, it can also cause radiating pain similar to radicular cervical spondylosis, including primary cervical spine tumor and cervical spine metastatic tumor. 5. Trauma: when the head and neck are struck by external force or twisted violently, it can cause soft tissue or cervical spine injury, which will lead to right-sided neck pain. 6. Neck strain: people with long-term head bowing or neck turning are prone to neck muscle strain, resulting in right-sided neck pain. The right side of the neck pain may also be related to pillow, cold, etc. It is recommended that patients go to the hospital as soon as possible to find out the cause of the pain, to be targeted treatment, do not delay to avoid aggravation of the condition.