A hernia occurs when part of an internal organ pushes through a tear or weak spot in surrounding muscle or tissue. Hernias most often affect the abdominal walls, which house the digestive system. The inguinal hernia, the most common type, affects up to 27% of people assigned male at birth and 3% of people assigned female at birth during their lifetime.

Though the exact cause of these holes or tears may not always be clear, hernias are linked to factors such as abdominal strain, aging, birth defects, and certain health conditions. This article explores the common causes and risk factors for hernias.

Acquired Hernia

A hernia typically forms when a weakness in the abdominal walls occurs during a person’s life. Aging naturally weakens muscles and tissues. When combined with factors that increase internal pressure, this weakening leads to perforations that cause internal organs to push through. This is the most common form of hernia, known as "direct" or acquired hernias.

Birth Defects

Some individuals are born with areas of weakness in the abdominal walls, which can lead to several types of hernias. The most common birth defect-related hernia is an umbilical hernia, where muscles around the belly button don’t fully form. Certain hiatal and inguinal hernias can also result from birth defects.

Is Hernia Hereditary?

While hernias have a significant genetic component, they are not directly hereditary. Having a family history of inguinal hernias increases the likelihood of developing one, making you four times more likely to get the condition. Mutations in genes related to elastin and collagen production, such as BF2, ADAMTS6, EFEMP1, and WT1, are linked to hernia development.

Who Gets Hernia?

Some individuals are more likely to develop a hernia. Risk factors vary based on age, sex, and other conditions.

Age

  • Inguinal hernia is common in children under 5 and people aged 75-80.

  • Hiatal hernia is more likely in people over 50.

  • Umbilical hernia occurs mostly in children under 2.

  • Incisional hernia commonly affects individuals aged 30-60.

  • Epigastric hernia is most common in preschool-age children.

  • Femoral hernia is more frequent in women aged 40-70.

Sex

  • People assigned male at birth are more likely to experience inguinal hernias, accounting for 90% of cases.

  • Femoral hernias are more common in people assigned female at birth, with women accounting for 70% of cases.

Risk Factors

Several factors increase the risk of developing a hernia, particularly those that put pressure on or weaken the abdominal walls. These include health conditions and lifestyle choices.

Abdominal Strain

Activities that put strain on the abdomen, such as constipation, chronic coughing, or sneezing, can contribute to hernia formation. Pushing during bowel movements or intense physical effort increases internal pressure, leading to a higher risk of a hernia.

Surgery

Having abdominal or pelvic surgery can increase the likelihood of developing a incisional hernia, which happens when abdominal walls don’t heal properly post-surgery. This is a common complication, affecting up to 20% of individuals who undergo abdominal surgeries.

Pregnancy

Pregnancy causes changes in collagen production, weakening abdominal walls. The growing fetus increases abdominal pressure, which can lead to the development of a hernia.

Obesity or Excess Weight

Excess weight puts pressure on abdominal organs, making them more likely to push through weak spots in the abdominal wall. Obesity, with a body mass index (BMI) of 30 or above, increases the risk of hernias.

Heavy Lifting

Heavy lifting or repetitive strain can cause internal pressure to increase, pushing organs through weak spots in the abdominal wall. While occasional lifting may not cause a hernia, persistent heavy lifting can lead to its development over time.

Tobacco Use

Smoking or using tobacco weakens abdominal walls and reduces collagen production, making it easier for hernias to form. Tobacco use also increases the chances of hernias returning after surgery.

Undescended Testicles

Inguinal hernias are more common in people with undescended testicles, a condition where one or both testicles fail to move into the scrotum before birth.

Certain Diseases

Health conditions associated with a higher risk of hernia include:

  • Chronic obstructive pulmonary disease (COPD)

  • Ehlers-Danlos syndrome

  • Marfan syndrome

  • Cystic fibrosis

  • Ascites (fluid buildup in the abdomen)

  • Enlarged prostate

A Quick Review

Hernias occur when internal organs, like the intestines or stomach, push through weak spots in the abdominal walls. Most hernias develop later in life, though one-third are due to birth defects. Risk factors for hernias include factors like heavy lifting, abdominal strain, pregnancy, obesity, and certain diseases.