A hernia is the protrusion of an organ through its containing wall. The term can be applied to the herniation of a muscle through its fascial covering, to the herniation of brain through a fracture of the
skull or through the foramen magnum into the spinal canal, as well as to the protrusion of an intraabdominal organ through a defect in the abdominal wall, pelvis or diaphragm.
Before an organ can herniate through its retaining wall there must be a weakness in that wall. This may be a normal weakness, found in everyone, and related to the anatomical configuration of the area
such as a place where a vessel or viscus enters or leaves the abdomen. Alternatively, the weakness may
be due to a congenital abnormality, or acquired as a result of trauma or disease.
■ inguinal
■ umbilical
■ incisional
■ femoral
■ epigastric.
In childhood, umbilical hernia is more common than inguinal hernia, it is important to have some knowledge of the rare types of abdominal herniae, because failure to diagnose any type of strangulated hernia, common or rare, may lead to the patient’s death. They are:
■ spigelian
■ obturator
■ lumbar
■ gluteal
Herniae occur frequently in both sexes. Inguinal hernia affects 9 per cent of men at some time in their lives and 1 per cent of women. Although the femoral hernia is found more often in women than in men, the commonest hernia in women is the inguinal hernia.
Certain physical signs are common to all herniae but are not always present:
■ they occur at congenital or acquired weak spots in the abdominal wall;
■ most herniae can be reduced;
■ most herniae have an expansile cough impulse.
The last two signs may be absent, especially if the hernia is tightly constricted at its neck, so their absence does not exclude the diagnosis of hernia.
The diagnosis of a hernia is therefore made initially by the site and confirmed by the presence of
reducibility and an expansile cough impulse. It may also be made when these signs are absent, by the
exclusion of other causes of a lump
