A lump in the abdomen is a soft bulge of tissue or a small, localized swelling on the abdomen. See also abdominal mass (a solid block of tissue that can be felt inside the abdomen).

Most often, a lump in the abdomen is caused by a hernia. An abdominal hernia occurs when there is an area where the muscles are weak, and this allows the internal organs to bulge through the abdominal wall.

A common type of hernia is an umbilical hernia (located around the belly button). This is caused by failure of the muscular ring around the navel to close completely. Umbilical hernias are more common in babies with a low birth weight, including premature babies. See also gastroschisis.

Incisions (from a previous surgery, for example) can leave the muscles weak in an area, and a hernia can form at the incision site. Incisional hernias may not appear until after straining, heavy lifting, or a prolonged period of coughing.

Umbilical hernias usually heal on their own without treatment, most often by the time the child is 4 years old.

Seek appropriate care for chronic cough or for constipation if you have a hernia. Straining associated with these conditions causes the intestines to protrude further into the hernia.

• A hernia becomes progressively larger, discolored, or painful.
• An umbilical hernia fails to heal by the time the child is 5 years old.
• A person with a hernia develops fever, vomiting, abnormal appearance of the hernia, or if the hernia is (or appears to be) painful or tender. A strangulated hernia, one in which the blood supply is lost to the organs that protrude through the hernia, is a (very rare) medical emergency!

The medical history will be obtained and a physical examination performed.

Medical history questions documenting your symptom in detail may include:

• Time pattern
  • When was the hernia first noticed?
  • Is it always there or does the bulge come and go?
• Location
  • Where is the bulge of the hernia located?
• Quality or size
  • How big is the hernia? Hint: try to measure the diameter (distance across) or compare to another object (the size of a baseball, for example).
• Aggravating factors
  • Have you noticed anything that makes the hernia bulge more?
• Relieving factors
  • Have you noticed anything that makes the hernia bulge less?
• Other
  • What other symptoms are also present?
  • Is there any pain or discomfort, discoloration of the skin, or other symptom associated with the hernia?
  • Are accompanying symptoms always there or only sometimes?

During the physical examination, several position changes may be required, or the patient may be asked to cough or strain.

Surgery may be needed to correct incisional hernias or umbilical hernias that do not resolve by the time the child approaches school age.

Emergency surgery is needed in the case of a strangulated hernia.