Enlargement of the joints of the little finger may be caused by local diseases such as trauma and infection, and systemic diseases such as gout and autoimmune diseases. 1. Local diseases: after trauma to the little finger, there will be swelling of the joints, subcutaneous bruising and so on, which may lead to the joints of the little finger to become larger; fracture, tendon rupture and so on, may form the fracture of the deformity of the healing, fibrous repair and so on, will also appear the above symptoms; finger infection, there will be redness, swelling and hot pain in the finger, can also lead to the joints to become larger, such as purulent phalangeal inflammation, and so on. 2. Systemic diseases: purine metabolism disorders in the body appear hyperuricemia leading to gout, may also appear in the small finger joints become larger, mainly due to uric acid crystals deposited in the joints and the body to react. Patients with autoimmune diseases such as rheumatism and rheumatoid diseases may also experience the above symptoms due to the reaction between rheumatoid factors and the body, resulting in localized bony encumbrances and synovial hyperplasia. The symptoms of enlarged joints of the little finger alone may not be able to accurately determine the cause of the problem, and it is necessary to combine with the characteristics of the medical history and other test results to make an accurate judgment, and it is recommended to clarify the cause of the disease under the guidance of a doctor.