Hernias explained

What a hernia is

The abdomen is held in by layers of muscle and tough tissue, a bit like a wall. If there is a weak point in that wall — present from birth, or developing with age, strain or after surgery — the contents inside can bulge through it. That bulge is a hernia. Most often it contains fat or a loop of bowel pushing through the gap. Typically it appears as a soft lump that may get bigger when you stand, cough, strain or lift, and disappear or shrink when you lie down or gently press it back. Many hernias cause little more than an occasional ache or a feeling of dragging. The concern is not the lump itself but the small chance that tissue becomes trapped.

The common types

The most common type is an inguinal hernia, which appears in the groin and is far more common in men. A femoral hernia also appears in the groin, lower down, and is more common in women; it carries a higher risk of complications. Umbilical and para-umbilical hernias appear at or near the tummy button and are common in babies, where they often close on their own, and in adults. An incisional hernia develops through the scar of a previous operation. A hiatus hernia is different: part of the stomach slides up through the diaphragm into the chest, and rather than a lump it tends to cause heartburn and acid reflux. Knowing the type helps guide whether and how it is treated.

Why hernias happen and who gets them

Hernias develop where a weak spot in the abdominal wall meets pressure pushing from inside. Some people are born with a weakness; others develop one with age as tissues become less strong. Anything that repeatedly raises pressure in the abdomen can contribute, including heavy lifting or straining, a long-term cough, constipation with straining, being overweight, pregnancy, and previous abdominal surgery, which leaves a potential weak point in the scar. Hernias cannot usually be prevented entirely, but staying a healthy weight, treating a persistent cough or constipation, and lifting carefully may reduce strain. Importantly, a hernia will not heal or go away on its own in an adult; it can only be repaired with surgery, though not every hernia needs an operation.

When a hernia becomes an emergency

Most hernias are harmless, but two complications make them urgent. In an incarcerated hernia, the tissue becomes trapped and can no longer be pushed back. In a strangulated hernia, the blood supply to that trapped tissue is cut off, which can quickly damage the bowel and become life-threatening. Warning signs include a hernia that suddenly becomes hard, very painful or tender, cannot be pushed back in, or turns red or dusky, especially with tummy pain, being sick, a swollen belly or being unable to pass wind or open the bowels. These signs mean you should get emergency help straight away. A strangulated hernia needs urgent surgery, so it is never something to wait and see about.

How hernias are treated

Many hernias that cause few symptoms can simply be watched, with the person told what warning signs to look out for. When a hernia is painful, growing, or at higher risk of complications — such as a femoral hernia — surgery is usually advised to repair the weak spot, often by placing a piece of mesh to strengthen the wall. This can frequently be done with keyhole (laparoscopic) surgery or as open surgery, sometimes as a day case. In babies, umbilical hernias are often left alone as many close by themselves in the first few years. A hiatus hernia is usually managed with measures to control acid reflux rather than surgery. A doctor can advise on the best approach for a particular hernia, weighing symptoms against the risks of surgery.