What causes umbilical hernia

What Causes Umbilical Hernias?

Umbilical hernias are a common condition, particularly in infants, characterized by a bulge near the belly button. Understanding their causes involves looking at both congenital (present at birth) and acquired (developing later) factors.

Causes in Infants

In newborns, the primary cause of an umbilical hernia is the incomplete closure of the abdominal muscles around the umbilical ring. Before birth, the umbilical cord passes through an opening in the abdominal muscles. After birth, this opening normally closes. However, if the muscles don't fully close, a small gap remains. This weak spot allows abdominal contents, such as a portion of the intestine or fatty tissue, to push through when intra-abdominal pressure increases. This pressure can be caused by crying, coughing, straining during bowel movements, or even just the normal activity of the baby.

Several factors can increase the likelihood of an umbilical hernia in infants:

• Prematurity and Low Birth Weight: Babies born prematurely or with low birth weight often have underdeveloped abdominal muscles, making them more susceptible.
• Multiple Births: Twins, triplets, or other multiples may have a higher incidence.
• Genetics: A family history of umbilical hernias can also play a role.

It's important to note that most infant umbilical hernias are not painful and typically resolve on their own as the abdominal muscles strengthen. This usually happens within the first few years of life, often by age 1 or 2, though some may take up to 5 years to close completely.

Causes in Adults

While umbilical hernias are less common in adults than in infants, they can develop due to a weakening of the abdominal muscles over time or due to increased pressure within the abdomen. Unlike infant hernias, adult umbilical hernias are less likely to resolve on their own and often require surgical intervention.

Factors contributing to adult umbilical hernias include:

• Increased Intra-abdominal Pressure: This is a significant factor. Conditions that raise pressure inside the abdomen can push abdominal tissues through the weakened umbilical ring. These include:
  • Obesity: Excess weight increases abdominal pressure.
  • Pregnancy: The growing uterus puts significant pressure on the abdominal wall.
  • Chronic Coughing: Conditions like chronic bronchitis or smoking can lead to persistent coughing.
  • Straining during Bowel Movements: Constipation or conditions requiring straining can contribute.
  • Ascites: The buildup of fluid in the abdominal cavity, often associated with liver disease.
  • Heavy Lifting: Repeatedly lifting heavy objects can strain the abdominal muscles.
• Previous Abdominal Surgery: Surgery in the umbilical area can weaken the abdominal wall.
• Weakened Abdominal Muscles: Age-related weakening or lack of muscle tone can predispose individuals to hernias.

The bulge associated with an adult umbilical hernia may become more noticeable when standing, coughing, or straining and may disappear when lying down. While some small adult umbilical hernias might not cause significant issues, larger ones or those that become incarcerated (trapped) can lead to complications like bowel obstruction or strangulation, which are medical emergencies.

Hernia vs. Other Belly Button Issues

It's important to distinguish an umbilical hernia from other conditions that might cause a bulge or discomfort around the belly button, such as an umbilical granuloma (common after the cord falls off), an umbilical cyst, or infection. A healthcare provider can accurately diagnose an umbilical hernia through physical examination.

When to Seek Medical Advice

For infants, it's generally recommended to monitor umbilical hernias unless they become very large, cause discomfort, or don't close by the age of 4-5. For adults, any new bulge near the belly button should be evaluated by a doctor. If a hernia causes pain, nausea, vomiting, or if the bulge cannot be pushed back in, immediate medical attention is necessary, as these could be signs of incarceration or strangulation.