Swelling and thickening of the second joint of the middle finger is usually considered to be caused by trauma or degenerative arthritis. If the second joint of the middle finger is swollen and thickened, the first step is to rule out the presence of trauma. In case of contusion or sprain of the middle finger, blood may accumulate locally, and in severe cases, damage to the joint capsule and ligaments, or even fracture or dislocation may occur, leading to swelling and thickening of the middle finger. If there is degenerative arthritis in the interphalangeal joints of the middle finger, it is usually due to too frequent activities of the fingers, which leads to strain of the finger joints, and the swelling and thickening of the second joint of the middle finger will also occur. For the swelling and thickening of the second joint of the middle finger, it is recommended to go to the orthopaedic department of a regular hospital as soon as possible, so that a professional orthopaedic surgeon can carry out physical examination and radiography, etc., to clarify the specific causes of the disease and carry out treatment in a timely manner.