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Hernia

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Hernia
A hernia is a defect in the abdominal wall allowing abdominal contents to protrude
out of the abdominal cavity. Trauma, surgery and increased intra-abdominal
pressure caused by such conditions as pregnancy, obesity, weight lifting or tumors
are risk factors for hernia formation.
Inguinal hernia
Inguinal hernias usually affect males and are classified as indirect or direct inguinal
hernias. Indirect inguinal hernias are caused by improper closure of the tract
developing as the testes descend into the scrotum before birth. A sac comprising
abdominal contents protrudes through the internal inguinal ring into the inguinal
canal. It often descends into the scrotum.
Although indirect inguinal hernias are congenital defects, these often are not evident
until adulthood, when increased intra-abdominal pressure and dilation of the
inguinal ring allow abdominal contents to enter the channel.
Direct inguinal hernias are acquired defects resulting from weakness of the posterior
inguinal wall. Direct inguinal hernias usually affect older adults.
Femoral hernias are also acquired defects in which a peritoneal sac protrudes
through the femoral ring. These hernias usually affect obese or pregnant women.
Inguinal hernias may produce no manifestations and are discovered during routine
physical examination.
These may cause a lump, swelling or bulge in the groin, particularly during lifting or
straining. An inguinal hernia may cause sharp pain or a dull ache radiating into the
scrotum. A palpable mass may be present in the groin, although it may be felt only
with increased intra-abdominal pressure (as occurs during coughing) and
invagination of the scrotum towards the inguinal ring.
Complications
The risk of complications is low with a reducible hernia. If the contents of a hernia
cannot be returned to the abdominal cavity, it is said to be incarcerated. Contents of
an incarcerated hernia are trapped, usually by a narrow neck or opening to the
hernia.
Incarceration increases the risk of complications, including obstruction and
strangulation. Obstruction occurs when the lumen of the bowel contained within the
hernia becomes occluded, much like crimping of a hose. A strangulated hernia
develops when blood supply to bowel and other tissues in the hernia sac is
compromised, leading to necrosis. The affected bowel infarcts; leading to
perforation and contamination of the peritoneal cavity. Clinical manifestations of a
strangulated hernia include severe abdominal pain and distension, nausea, vomiting,
tachycardia and fever.
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