Umbilical hernia is a type of extra-abdominal hernia. When an organ or tissue in the abdominal cavity protrudes outside the abdominal cavity through a congenitally existing or acquired orifice or weak area for various reasons from its normal anatomical site, it is called an extra-abdominal hernia. An umbilical hernia is a hernia in which the hernia sac protrudes through the umbilical ring. Clinically, it can be divided into infantile umbilical hernia and adult umbilical hernia, which have different causes and treatment methods. 1. Infantile umbilical hernia: It occurs due to incomplete closure of the umbilical ring during the embryonic period or the scar tissue of the umbilicus is not strong enough. The typical symptom is a reversible mass protruding from the umbilicus, which is especially noticeable when the baby cries and disappears when the baby is quiet. It is extremely rare for an infant to have an umbilical hernia that is embedded or strangulated. However, it is important to note that after trauma, the covering tissue of an infant umbilical hernia can be punctured, resulting in an exposed bowel. 2. Adult umbilical hernia: It is acquired and does not exist in childhood, but arises in adulthood due to weakness of the abdominal wall and excessive intra-abdominal pressure for various reasons, and is mostly seen in obese people with weak abdominal wall, middle-aged and elderly people and menstruating mothers, as well as in patients with chronic diseases such as cough, constipation and cirrhotic ascites with increased intra-abdominal pressure. The main clinical manifestation is a round hernia protruding from the umbilicus upon standing, coughing and exertion, which disappears after lying down. When the mass is retracted, a defect in the abdominal wall can be visualized. Smaller umbilical hernias may be asymptomatic, but if more omentum and intestine protrude, abdominal pain and abdominal discomfort may be present. In adults, umbilical hernias are more likely to become entrapped and strangulated than in infants, and may present with sudden onset of severe pain, inability to retract the mass, and mechanical intestinal obstruction if the contents are intestinal. In principle, children over 5 years of age with infantile umbilical hernia should be treated surgically, and surgery is the first choice to cure adult umbilical hernia.