A hernia is the protrusion of an organ or the fascia of an organ through the wall of the cavity that normally contains it. There are different kinds of hernia, each requiring a specific management or treatment.
By far the most common hernias develop in the abdomen, when a weakness in the abdominal wall evolves into a localized hole, or “defect”, through which adipose tissue, or abdominal organs covered with peritoneum, may protrude. Another common hernia involves the spinal discs and causes sciatica. A hiatal hernia occurs when the stomach protrudes into the mediastinum through the esophageal opening in the diaphragm.
Hernias may or may not present with either pain at the site, a visible or palpable lump, or in some cases more vague symptoms resulting from pressure on an organ which has become “stuck” in the hernia, sometimes leading to organ dysfunction. Fatty tissue usually enters a hernia first, but it may be followed or accompanied by an organ.