• Clinical science

Abdominal hernias


Abdominal hernias are defined as the abnormal protrusion of intra-abdominal contents through congenital/acquired areas of weakness in the abdominal wall. The four categories of anatomically-classified abdominal hernias include the following: ventral hernias (e.g., epigastric, umbilical, incisional hernias), groin hernias (inguinal and femoral hernias), pelvic hernias (obturator, sciatic, and perineal hernias), and flank/lumbar hernias. Groin hernias are discussed in more detail in their respective articles. Inguinal, incisional, and umbilical hernias are the most common types of hernias. Persistently raised intra-abdominal pressure (e.g., due to ascites, pregnancy, intra-abdominal tumors, chronic cough, etc.) increases the risk of developing an abdominal hernia. Uncomplicated hernias are asymptomatic, nontender, and completely reducible with an expansile cough impulse. Complicated hernias include incarcerated, obstructed, and strangulated hernias and are characterized by tenderness, irreducibility, features of bowel obstruction, and an absent cough impulse. Abdominal hernias are often diagnosed on clinical examination. Imaging (e.g., ultrasound, CT scan) is used to confirm the diagnosis and evaluate the contents of the hernia. Complicated hernias and those with a narrow neck (e.g., femoral hernia, obturator hernia, paraumbilical hernia) should be surgically repaired (primary repair/mesh repair). Congenital umbilical hernias typically close spontaneously by 5 years of age, have a wide neck, and a low risk of complications; surgical intervention is rarely necessary.


Ventral hernias

Groin hernias

Pelvic hernias (rare)

Flank hernias


Clinical features

Reducible hernia

  • Hernial contents completely return to the abdominal cavity through the abdominal wall defect on lying down or upon application of mild external pressure.
    • Most reducible hernias manifest as an asymptomatic nontender mass.
      • Increases on straining (e.g., sitting up from a recumbent position)
      • Decreases completely on lying down
    • Visible cough impulse present: expansion of the hernia when the patient is asked to cough
    • Edges of the fascial defect are palpable
    • Bowel sounds may be heard over the mass (if the hernial content is bowel)

Irreducible/incarcerated hernia

  • Hernial contents become adhered to the hernial sac and cannot be reduced into the abdominal cavity.
    • Irreducible nontender mass
    • Visible cough impulse present
    • May decrease partially on lying down
    • Increased risk of obstruction and strangulation

Obstructed hernia

  • The abdominal wall defect acts as a tourniquet around the hernial contents, causing edema and distension of the hernial contents.

Strangulated hernia

The smaller the hernial orifice, the higher the risk of incarceration!



  • Usually a clinical diagnosis
  • Imaging: indicated if the diagnosis is unclear and/or to identify contents of the hernial sac (e.g., loops of bowel)
    • Ultrasound: especially useful to identify ventral hernias (e.g., epigastric, Spigelian, incisional, or umbilical hernia)
    • IV and oral contrast enhanced CT scan: useful for suspected hernias that may be difficult to identify on physical examination (e.g., lumbar, obturator, perineal or sciatic hernia)
    • Findings: abdominal wall defect with/without protrusion of intra-abdominal contents through it
    • Abdominal x-ray


Differential diagnoses

The differential diagnoses listed here are not exhaustive.


  • Surgical hernia repair is recommended for the management of most abdominal hernias.
    • Surgery: open or laparoscopic tension-free closure of the abdominal wall defect with/without a mesh
    • Elective surgery is indicated in reducible and incarcerated hernias.
    • Emergency surgery is indicated in obstructed or strangulated hernias.
  • Conservative management (observation) is indicated in:
    • Congenital umbilical hernia in children < 5 years of age
    • Asymptomatic wide-necked hernias in patients with high operative risk: A truss or corset may be considered in these patients to decrease the risk of obstruction and strangulation.

Incisional hernia

  • Definition: Herniation of intra-abdominal contents through an abdominal wall defect created during a previous abdominal surgery.
  • Incidence: ∼15% of patients who have undergone abdominal surgery develop incisional hernias.
  • Risk factors
    • Upper midline laparotomy incisions (highest risk)
    • Wound dehiscence
    • Postoperative wound infection
    • Poor wound healing
    • Emergency abdominal surgeries
  • Clinical features
    • Most (∼ 75%) incisional hernias occur within 3 years of surgery
    • Mass/protrusion at the site of the incisional scar which increases with coughing/straining
    • Edges of the hernial defect can be palpated on reducing the hernia
  • Treatment
    • Conservative management is indicated in:
      • Asymptomatic incisional hernias, with a wide neck;
      • Patients who are at a high anesthetic risk (advanced age, multiple comorbidities)
    • Surgery is indicated in symptomatic/complicated hernias or those with a narrow neck.
      • Small incisional hernias (< 3 cm defect): primary repair
      • Larger incisional hernias: hernioplasty (mesh repair)


Umbilical hernia

Congenital umbilical hernia

Acquired umbilical hernia

(Paraumbilical hernia)

  • Accounts for ∼ 5% of all adult abdominal hernias
Site of hernial defect
  • Umbilical orifice
  • Adjacent to the umbilical orifice (superior/inferior/lateral)
  • Failed spontaneous closure of the umbilical ringpatent umbilical orifice
  • Acquired abdominal wall defect
Risk factors
  • Persistently raised intra-abdominal pressure
Clinical features
  • Mass protruding through the umbilicus
  • Mass increases on crying/coughing/straining; reduced in size on lying down
  • Hernia can be completely reduced (unless incarcerated)
  • Mass protruding adjacent to the umbilical orifice pushing the umbilicus into a crescent shape
  • Fascial defect is small

Risk of developing complications


  • Low
  • High
  • Conservative: ∼ 90% will spontaneously close by 5 years of age
  • Surgery (rarely necessary)
    • Large umbilical hernias (defect > 2 cm or protuberant hernias)
    • No evidence of spontaneous closure by 5 years of age
    • Incarcerated, obstructed, or strangulated umbilical hernias
  • Surgery (primary repair/mesh plasty): all paraumbilical hernias
Differential diagnosis


last updated 07/03/2020
{{uncollapseSections(['3iaSr4', '4Vc3uY0', 'kiam74', 'OVcIuY0', 'PVcWuY0', 'MiaMH4', 'Qlcu9c0', 'Rlcl9c0'])}}