The common causes of big lesser toes swelling and pain are as follows: first, gout: big lesser toes swelling and pain, the most common cause is caused by gout, gout is the most common site for the big lesser toes of the toes of the area, there can be swelling and pain, the serious can be accompanied by redness of the skin as well as elevated skin temperature, to check the blood uric acid to diagnose. Secondly, lesser ectopia: lesser ectopia can lead to bursitis of the bursa at the root of the big lesser toe, and the swelling and pain at the root of the big lesser toe on the outside of the big lesser toe. It can affect walking and restrict the movement of the foot, which needs to take X-ray film of the foot and physical examination for diagnosis and treatment. Third, infectious diseases: bacterial infection or tuberculosis infection of the big lesser toe can also lead to the swelling and pain of the big lesser toe. Fourth, tumor: if there is tumor growth in the soft tissue of the bone of the big lesser toe, it can also lead to the swelling and pain of the big lesser toe, which should be diagnosed and treated by physical examination and MRI examination of the big lesser toe.