Navel, umbilical cord, commonly known as umbilical eye, is called "Shenque" in Chinese medicine, which is essentially a scar left by the umbilical cord after the fetus is born. The navel is located on the midline of the abdomen at the level of the anterior superior iliac spine, and its diameter is about 1.0 ~ 2.0 cm. Usually it can be a small depression or a small protrusion. The abdominal muscles below the navel form a depression. Thin navel usually brings some structural weaknesses, making it prone to umbilical hernia.