Abdominal masses are usually only on the surface of the abdomen, and irregular abnormal masses are felt inside the abdominal cavity, usually classified as round, oval or tubular, striated, etc. If a mass is felt in the right lower abdomen in the form of a cord, it may be acute appendicitis. If a mass is felt in the lower abdomen on both sides or in the middle of the lower abdomen, it may be a gynecological mass. If the mass is felt in a superficial location under the skin, it may be a superficial subcutaneous mass, such as sebaceous cyst, lipoma, fibroid, etc. If the mass is felt deep in the abdominal cavity and is round, it may be a tumor in the intestine, which can be basically diagnosed by local ultrasound or CT or MRI.