Thumb tenosynovitis is mainly characterized by thumb pain, redness, swelling, and restricted movement. 1. Pain: Due to the inflammation of the tendon sheath of the thumb irritating the surrounding tissues as well as the nerve endings, the patient may have pain in the thumb and pressure pain at the metacarpophalangeal joint. 2. Redness and swelling: due to the inflammatory reaction of edema and exudation of tenosynovitis, patients may experience redness of the surrounding skin and localized swelling. 3. Restriction of activities: long-term inflammatory reaction leads to the restriction of thumb flexion and extension activities, which is more obvious in the morning, and the disease can develop to the later stage of joint stiffness and popping sound when moving. Patients with thumb tenosynovitis are advised to go to the hospital in time for early treatment to minimize the adverse effects of the disease.