A hernia is defined as the protrusion of an organ or tissue through a defect or weakness in the containing wall of its natural cavity most commonly the abdominal wall. Hernias are classified by their anatomical location: inguinal hernias are further subdivided into indirect inguinal hernias passing through the deep inguinal ring along the path of the spermatic cord and direct inguinal hernias, which protrude through a weakness in the posterior wall of the inguinal canal (Hesselbach's triangle). Other common types include femoral hernias (more prevalent in women, carrying a high risk of strangulation), umbilical hernias, paraumbilical hernias, incisional hernias (occurring through previous surgical scars) and epigastric hernias. Predisposing factors include raised intra-abdominal pressure from chronic cough, constipation, heavy lifting, obesity, pregnancy and ascites alongside congenital weakness of the abdominal wall musculature.
Symptoms
Many hernias are initially asymptomatic, presenting simply as a visible or palpable lump that the patient notices typically in the groin, umbilicus or along a previous surgical scar. The swelling characteristically appears on straining, coughing or standing and reduces on lying down or gentle manual pressure a feature termed reducibility. A dull aching discomfort or dragging sensation at the hernia site is common, worsening with prolonged standing or physical exertion. The two critical complications that define surgical urgency are incarceration where the hernia contents become irreducible and trapped within the sac and strangulation, where the blood supply to the herniated contents is compromised leading to ischaemia and necrosis. Strangulation presents as a tense, tender, irreducible swelling accompanied by severe continuous pain, vomiting and signs of bowel obstruction constituting a genuine surgical emergency demanding immediate operation.
Diagnosis
The diagnosis is primarily clinical, based on history and careful physical examination. The hernia is assessed for its site, size, reducibility and the presence of a cough impulse. The distinction between inguinal and femoral hernias is made anatomically inguinal hernias arise above and medial to the pubic tubercle, while femoral hernias arise below and lateral to it. Ultrasound is the first-line imaging investigation when the diagnosis is uncertain, particularly for occult or small hernias not readily apparent on examination. CT scan is reserved for complex cases large incisional hernias, recurrent hernias or when strangulation is suspected providing detailed mapping of hernia contents, defect size and relationship to adjacent structures, which is essential for surgical planning.
Treatment
All symptomatic hernias and all femoral hernias regardless of symptoms, owing to their high strangulation risk warrant surgical repair. Watchful waiting is acceptable only for minimally symptomatic inguinal hernias in elderly or high-risk patients, though the risk of emergency presentation must be discussed. Laparoscopic mesh repair is the gold standard for elective inguinal hernia surgery either TAPP (Transabdominal Preperitoneal) or TEP (Totally Extraperitoneal) approach placing a synthetic mesh behind the abdominal wall to reinforce the defect, offering significantly lower recurrence rates, less post-operative pain and faster return to activity compared to open repair. Open mesh repair (Lichtenstein technique) remains widely performed and is the preferred approach for unfit patients or those under local anaesthesia. For incisional and ventral hernias, laparoscopic or open component separation with mesh reinforcement is tailored to defect size and complexity. Strangulated hernias require emergency surgery with bowel resection if ischaemic intestine is encountered, followed by primary repair or delayed mesh placement depending on the degree of contamination.