Snapping fingers are also known as tendinitis of the flexor muscles of the fingers. It may be related to chronic strain, infection, and injury. Patients can be treated by applying anti-inflammatory and pain relieving ointment, ointment of antibacterial drugs and antibiotic ointment. 1. Chronic strain: When the fingers are frequently extended and flexed, the tendons are subjected to excessive friction, which may lead to inflammation. It can be treated by applying anti-inflammatory ointment such as ibuprofen ointment and mupirocin ointment. 2. Infection: When the tendon sheath area is stabbed or when tendon sheath injections are performed, bacteria will enter the tendon sheath tissue along with the wound, triggering infectious tenosynovitis. It can be treated by applying ointment with antibacterial drugs such as erythromycin ointment and mupirocin ointment. 3. Injury: If tendons and tendon sheaths are acutely injured, tendovaginitis can occur. Ointments of antibiotics such as fusidic acid cream and ofloxacin ointment can be applied for treatment. When finger flexor tenosynovitis occurs, the patient should go to the regular hospital in a timely manner, to clarify the cause of the disease and then carry out treatment. Follow the doctor’s instructions to use medication, do not use medication privately.