If a bulge grows on the back of the foot, you can hang the dermatology department for consultation; 2, if the bulge is a proliferative reaction formed under the skin, it may be a tendon sheath cyst, you can hang the orthopedics department; 3, if it is a subcutaneous lump and has a certain activity, it may also be a subcutaneous cyst or subcutaneous lipoma, etc., this time you can hang If the bulge is above the skin surface, it may be a localized common wart, which is also a dermatological disease, so it needs to be registered with the dermatology department and can be treated with laser or cryotherapy.