A hernia occurs when an internal body part protrudes through a weakened area of surrounding muscle or tissue that would usually be able to contain it. Hernia are very common and estimates suggests that around one in ten of us develops a hernia at some point in their lifetime.
In the majority of cases, hernia develop in the abdomen, caused by a weakness in the abdominal wall that eventually leads to an opening or “defect” developing. Tissues or organs that usually push against the abdominal wall then push through the wall instead. The resulting bulge, which can often been seen underneath the skin, is referred to as a hernia.
The most common type of hernia is the inguinal hernia, which occurs when a part of the bowel or fatty tissue squeezes through the abdominal wall into the groin area. This form of hernia is often associated with aging or straining of the abdomen. Another common hernia is the femoral hernia, where a bowel part or fatty tissue protrudes into the groin area, at the top of the inner thigh. Femoral hernias are also linked to ageing and abdominal strain. Another well known form of hernia is the hiatus hernia, where a part of the stomach pushes through into the chest through a weak point in the diaphragm. The cause of this hernia is not well understood, but may be related to the diaphragm becoming weaker as a person ages.
In many cases, hernia cause no or only mild symptoms, but depending on how severe the condition is, hernia can cause several complications. Inguinal hernias, for example, may gradually increase in size and eventually press on the scrotum in males, leading to pain and swelling. In the case of hiatus hernia, stomach acids may leak into the esophagus causing heartburn, regurgitation, and even bleeding.
Most hernias are reducible, which means that the herniated contents can be manipulated back into the abdominal cavity. However, some hernias are irreducible (also called incarcerated hernias) and cannot be pushed back to their original location. This can lead to the following complications:
- Strangulation - Pressure placed on the hernial contents may compromise the blood supply to a section of an organ or tissue, leading to ischemia, cell death and even gangrene. A strangulated hernia is life threatening and requires immediate surgery
- Obstruction - When part of the gut herniates, the bowel contents may no longer be able to pass through the herniated area, leading to cramps, absence of defecation and vomiting.
Due to the risk of a hernia becoming strangulated or causing obstruction, people with the condition should visit their accident and emergency department if they develop any of the following symptoms:
- Sudden and severe pain
- Nausea and vomiting
- Wind and constipation
- Hernia feels tender or firm and won’t move back into its original location
A strangulated hernia or obstructed bowel are life-threatening conditions that require immediate surgical treatment.
Complications after surgery
A hernia operation is one of the most common surgical procedures performed worldwide, with over 100,000 of these surgeries carried out every year in the UK alone. Although the procedure is generally safe, there is a small risk of complications occurring after surgery.
After inguinal hernia surgery, for example, males may experience painful swelling in the scrotum or the presence of gangrene may lead to perforation of the bowel. Other serious problems that may occur after a hernia operation include infection, numbness at the surgery site, and recurrence of the hernia.
Another complication that can occur post-operation is rejection of the mesh used to repair the hernia, in which case the mesh will need to be removed. This can usually be detected through symptoms such as swelling and pain in the area where the mesh was placed. Once the mesh is removed, discharge from the surgical wound is likely to persist for a period.
The risk of complications occurring after surgery are more likely in cases where the following apply:
- Age over 50 years
- The hernia has been present for under one year
- There is comorbidity such as heart disease