Causes
The causes of umbilical hernia are congenital and acquired malformation, but an apparent third cause is really a cause of a different type, a paraumbilical hernia. Congenital
Congenital umbilical hernia is a congenital malformation of the navel (umbilicus). Among adults, it is three times more common in women than in men; among children, the ratio is roughly equal. It is also found to be more common in children of African descent. Acquired
An acquired umbilical hernia directly results from increased intra-abdominal pressure caused by obesity, heavy lifting, a long history of coughing, or multiple pregnancies. Another type of acquired umbilical hernias are incisional hernias, which are hernia developing in a scar following abdominal surgery, e.g. after insertion of laparoscopy trocars through the umbilicus. Paraumbilical
Importantly, an umbilical hernia must be distinguished from a paraumbilical hernia, which occurs in adults and involves a defect in the midline near to  the umbilicus, and from omphalocele. Diagnosis
Navels with the umbilical tip protruding past the umbilical skin ("outies") are often mistaken for umbilical hernias, which are a completely different shape. Treatment for cosmetic purposes is not necessary, unless there are health concerns such as pain, discomfort or incarceration of the hernia content. Incarceration refers to the inability to reduce the hernia back into the abdominal cavity. Prolonged incarceration can lead to tissue ischemia (strangulation) and shock when untreated. Umbilical hernias are common. With a study involving Africans, 92% of children had protrusions, 49% of adults, and 90% of pregnant women.
In general, the child needs to stay in the hospital for 1 day and the healing is complete within 8 days.At times, there may be a fleshy red swelling seen in the hollow of the umbilicus that persists after the cord has fallen off. It may bleed on touch, or may stain the clothes that come in contact with it. This needs to be shown to a pediatric surgeon. This is most likely to be an umbilical polyp and the therapy is to tie it at the base with a stitch so that it falls off and there is no bleeding. Alternatively, it may be an umbilical granuloma that responds well to local application of dry salt or silver nitrate but may take a few weeks to heal and dry. Adults
Many hernias never cause any problems, and do not require any treatment at all. However, because the risk of complications with age are higher and the hernia is unlikely to resolve without treatment, surgery is usually recommended.Usually hernia has content of bowel, abdominal fat or omentum, tissue that normally would reside inside the abdominal cavity if it wasnt for the hernia. In some cases, the content gets trapped in the hernia sac, outside the abdominal wall. The blood flow to this trapped tissue may be compromised, or the content even strangulated in some cases. Depending on the severity and duration of blood flow compromise, it can cause some pain and discomfort.