What is hernia?|
A hernia is the protrusion of an organ through an opening in the cavity in which it is contained. For example the extension of a muscle through its covering. The most common type of hernia involves the protrusion of an abdominal organ (eg the stomach or intestines) through the abdominal wall.
Most hernias are able to be pushed back into their cavity (reducible), however the greatest risk is that the organ may get stuck outside the cavity (incarcerated). In this scenario, the blood supply to the organ may get cut off causing gangrene of that segment (strangulation). The most common herniae are abdominal herniae that occur in the groin area in 75% of cases.
What causes herniae?
For an organ to protrude from its cavity there must be a weakness in the cavity wall. This may be a normal weakness that occurs in all people as a result of the structural arrangement of muscles and tissues. There are also some abnormal causes of weakness that can be divided into:
- Congenital - this means that the person is born with the weakness. Fo example,in the case of inguinal groin hernias where canal in the abdominal wall fails to shut off.
- Acquired - here the weakness in the cavity wall develops as a result of another factor such as degeneration of tissues with age, smoking or illness. Persistent high pressure in the cavity can also cause a weakness in the wall, for example long-term straining as a result of constipation can weaken the abdominal wall.
The hernia may develop suddenly at the time of a sudden forceful muscular effort (eg lifting), or it may develop slowly over time.
What are the symptoms of hernia?
Characteristically the person with a hernia will notice an unusual lump. Initially this lump may disappear when the person pushes on it (reducible) or when the patient lies down. With coughing or straining, pressure is increased, and the lump typically has an impulse which can be felt with the hand.
Discomfort may occur, and this is usually felt as a dragging feeling or an ache that is worse at the end of the day, and relieved at night when the person lies down.
If the intestine gets obstructed by its protrusion outside of the cavity, the sufferer may experience signs of bowel obstruction. These include severe pain, vomiting, swelling of the abdomen, and absolute inability to pass a bowel motion (constipation).
The common sites where a lump occur are as follows:
- Inguinal hernia - lump around the scrotum (males), or genitals (females).
- Femoral hernia - lump around the groin crease.
- Incisional hernia - lump at the site of an old wound/scar.
- Umbilical hernia - lump which protrudes through the belly-button. Common in babies, usually disappears in the first few months.
- Overall, herniae are more common in males.
- Femoral herniae are more common in females.
- There is a greater occurrence of herniae in certain occupations, for example those jobs involving heavy lifting.
- Herniae most commonly occur in the first few months of life, in the late teens/early 20's, and in the 40-60 year age bracket.
- It is the most common surgical problem seen by family doctors.
- The chance of having a hernia sometime over the lifespan is about 10%.
How are herniae diagnosed?
The diagnosis is usually made on careful physical examination looking for the key features of all herniae (a reducible lump with a cough impulse). Ultrasound scans may be useful in the diagnosis of inguinal herniae; and for people who report symptoms but do not have a lump.
How is it treated?
The first and most important line of treatment is to find and correct any causative factors, such as constipation or chronic cough. Non-surgical treatment consists of wearing a 'truss' which is a specially fitted brace that is worn to apply external press