Neck pain accompanied by dry mouth may be caused by tonsillitis, pharyngitis, subacute thyroiditis and other reasons. 1. Tonsillitis: Infection by pathogenic microorganisms can cause inflammation of the tonsils, which can lead to pharyngeal pain, difficulty in swallowing, dry mouth, and inflammation can also involve the lymph nodes in the neck, resulting in lymph node enlargement, which can be accompanied by neck pain. 2. Pharyngitis: viral and bacterial infections or environmental stimuli can cause inflammation of the pharynx, which can lead to symptoms of dry mouth, mostly involving the pharynx and lymphatic tissues in the neck, resulting in lymphatic enlargement, which can lead to neck pain. 3. Subacute thyroiditis: Subacute thyroiditis can be characterized by neck pain and dry mouth in the hyperthyroid phase. If the neck pain is accompanied by dry mouth symptoms that persist, you need to seek medical attention.