In babies, umbilical hernias form when the abdominal muscles near the navel fail to close up completely after birth, Mayo Clinic states. Excessive pressure on the abdomen causes umbilical hernias in adults, and the condition may be triggered by risk factors such as obesity, surgery, multiple pregnancies or fluid buildup.
Before birth, the umbilical cord is connected to a fetus's body through an opening in the abdominal wall, Medical News Today explains. The muscles normally join together within 12 months of the umbilical cord being cut, but a hernia may form when the bowel or fatty tissue pushes through the weakened muscle. The hernia usually causes a small bulge around the navel, which is more pronounced when a baby coughs, cries, laughs or has a bowel movement. When a baby is lying down, the lump may be less noticeable. Abdominal pressure caused by persistent coughing or heavy lifting are additional risk factors for adults.
Pain and abdominal discomfort are common symptoms in adults, but children rarely suffer any pain or complications, according to Mayo Clinic. However, doctors recommend medical treatment if adults or children experience vomiting or develop tenderness, swelling, discoloration or pain at the hernia site. These symptoms may occur when the hernia is stuck in the abdominal opening, known as incarceration, and the blockage reduces blood flow in part of the intestine. Left untreated, this condition can completely halt blood flow, known as strangulation, and cause the affected tissue to die and spread infection.