Thumb joint pain may have the following causes: First, ankylosing spondylitis, ankylosing spondylitis can often lead to pain in the metacarpophalangeal joint of the thumb, which can be accompanied by morning stiffness, and in severe cases, there will be popping and restricted movement, which should be investigated early, and if necessary, closed treatment or surgery; Second, gout, when gout involves the finger joints, there can be pain in the thumb The pain of the joints can be accompanied by joint swelling and elevated skin temperature, and blood tests for uric acid should be performed for early diagnosis and treatment.