There are many reasons for bulging feet, such as cysts, boils, tumors, mosquito bites and other causes. 1. Cysts: tendon sheath cysts, for example, are cystic swellings that occur in the tendon sheaths of joints and are caused by degeneration of the connective tissues, which can lead to bulges on the feet. 2. Boils: Infections deep in the skin follicles, resulting in a purulent inflammatory reaction, may also appear in the early stages of subcutaneous hard lumps, resulting in foot bulges. 3. Tumors: local benign soft tissue tumors, malignant tumors or bone tumors, etc., may lead to foot bulges. 4. Mosquito bites: mosquito bite venom stimulation, may also cause local skin inflammatory reaction and allergic reaction, manifested in the symptoms of foot long bulge. There may be other reasons for the long feet, you should go to the hospital in time for further examination to clarify the cause of the disease, and follow the doctor’s instructions for treatment.