Sore thumb muscles may be caused by trauma, tenosynovitis, carpal tunnel syndrome and other reasons. 1. Trauma: When the thumb is strained by trauma, local tissue edema can occur, resulting in sore thumb muscles. 2. Tenosynovitis: chronic inflammation of the tendon sheath of the flexor digitorum longus can be caused by prolonged labor or localized exposure to cold, resulting in symptoms of muscle pain. 3. Carpal tunnel syndrome: the median nerve in the carpal tunnel pressure caused by the disease, often with a history of occupational disease or history of strain injury, can lead to thumb muscle pain. Thumb muscle pain should go to the regular hospital in time, to clarify the cause of the disease, under the guidance of the doctor for standardized treatment, so as not to delay the condition.