Tendinitis mostly occurs in the wrist joints that frequently flex and extend, as well as in the thumb and corresponding metacarpophalangeal joints. It is largely due to the repetitive flexion and extension movements of the fingers and wrist joints, such as those performed by noodle makers in restaurants, vegetable cutters, and some handcraft laborers. Repeated movements irritate the local tendon sheaths causing inflammation, leading to relative narrowing, which prevents the tendons from flexing and moving normally. This results in a condition known as stenosing tendinitis. These are the common causes and symptoms of the condition, enabling a clear diagnosis.