Inguinal Hernia

Abdominal wall Groin hernia

A loop of bowel or fat pushing through a weak spot in the groin's muscle wall, forming a bulge.

Educational summary only — not medical advice, and no substitute for assessment by a clinician. Diagrams are simplified illustrations.

A weak spot in the groin's muscle wall lets a loop of bowel push through, creating a bulge that often pops out on straining.

Overview

A hernia is when an internal structure — usually a loop of intestine or some fatty tissue — pushes through a weak spot in the muscle wall meant to contain it. An inguinal hernia occurs in the groin and is the most common type. It shows as a bulge that often appears on straining and may slip back when you lie down.

How the system normally works

The abdominal organs are held in by layered muscle and connective tissue. The groin contains a natural channel (the inguinal canal) through which structures pass to the genitals; this canal is a built-in weak point that can stretch or give way.

What goes wrong

When the wall at this weak point gives, pressure from coughing, lifting or straining pushes a sac of tissue — often containing bowel — through the gap, producing a bulge. Usually the contents slide back in (reducible). Sometimes they get stuck (incarcerated); if the trapped bowel's blood supply is then cut off (strangulated), that segment is in danger and the situation becomes an emergency.

Diagram of three hernia stages: reducible, incarcerated, and strangulated with the trapped bowel losing its blood supply. — A hernia can be reducible (pushes back in), incarcerated (stuck), or strangulated (stuck with its blood supply cut off) — the last is an emergency.

Symptoms and why they happen

A groin bulge, more obvious on standing, coughing or straining — tissue pushed through the gap.
An aching or dragging sensation, often worse by day's end.
A bulge that disappears on lying down — contents sliding back.
Sudden severe pain, a hard tender lump, and vomiting — warning of strangulation.

Causes and risk factors

Male sex (much more common)
Increasing age and weakened tissues
Chronic coughing, straining, or heavy lifting
Constipation or difficulty passing urine
Obesity and previous groin surgery

How it's diagnosed

Usually a clinical diagnosis — a clinician sees and feels the bulge, often asking you to cough or stand. Ultrasound or other imaging is used when the diagnosis is unclear.

Diagram of the groin showing the locations of indirect inguinal, direct inguinal, and femoral hernias. — Groin hernias come through slightly different routes — indirect and direct inguinal hernias through the inguinal canal, femoral hernias lower down.

Treatment and management

The definitive treatment is surgical repair, pushing the contents back and reinforcing the wall, usually with a mesh, by open or keyhole technique. Small, painless hernias in some people may simply be watched. An incarcerated or strangulated hernia needs emergency surgery.

Possible complications

Incarceration, strangulation with dead bowel, and bowel obstruction. Repaired hernias can occasionally recur.

Prevention and outlook

Maintaining a healthy weight, avoiding constipation, and using good technique when lifting reduce strain on the groin. Repair is a common, generally low-risk operation with a good outlook.

When to seek emergency care

A hernia that becomes hard, very painful, and won't push back in, especially with vomiting — possible strangulation; emergency.
The overlying skin turning red or dusky.