A raised lump of flesh in the navel may be caused by umbilical hernia, lipoma, sebaceous cysts, boils and so on. 1. Umbilical hernia: the organs and tissues in the abdominal cavity are protruding through the umbilicus to the umbilicus or to the body surface around the umbilicus under the action of many factors, which may be manifested as a raised lump of flesh. 2. Lipoma: mostly occurs in the umbilicus between the subcutaneous and muscle, can be manifested as a lump raised. 3. Sebaceous cysts: the sebaceous gland secretions at the navel cannot be discharged normally, and sebaceous cysts are formed, which are manifested as raised meatballs. 4. Boils: If one of the hair follicles in the navel area is infected by bacteria and forms a boil, it can form a lump. It is recommended that people with a bulging flesh in the navel go to the hospital in time to clarify the cause of the disease and standardize the treatment under the guidance of the doctor.