June 14, 2010
Dr. Dustin Smith
A hernia occurs when the contents of a body cavity bulge out of the area where they are normally contained. These contents, usually portions of intestine or abdominal fatty tissue, are enclosed in the thin membrane that naturally lines the inside of the cavity. Although the term hernia can be used for bulges in other areas, it most often is used to describe hernias of the lower torso (abdominal-wall hernias).
Hernias by themselves may be asymptomatic (produce no symptoms), but nearly all have a potential risk of having their blood supply cut off (becoming strangulated). If the blood supply is cut off at the hernia opening in the abdominal wall, it becomes a medical and surgical emergency as the tissue needs oxygen transported by the blood supply. Different types of abdominal-wall hernias include the following:
- Inguinal (groin) hernia: Making up 75 percent of all abdominal-wall hernias and occurring up to 25 times more often in men than women, these hernias are divided into two different types, direct and indirect. Both occur in the groin area where the skin of the thigh joins the torso, but they have slightly different origins. Both of these types of hernias can similarly appear as a bulge. Distinguishing between the direct and indirect hernia, however, is important as a clinical diagnosis.
- Indirect inguinal hernia: An indirect hernia follows the pathway that the testicles made during fetal development, descending from the abdomen into the scrotum. This pathway normally closes before birth but may remain a possible site for a hernia later in life. Sometimes the hernia sac may protrude into the scrotum. An indirect inguinal hernia may occur at any age.
- Direct inguinal hernia: The direct inguinal hernia occurs slightly to the inside of the site of the indirect hernia, in an area where the abdominal wall is naturally slightly thinner. It rarely will protrude into the scrotum. Unlike the indirect hernia, which can occur at any age, the direct hernia tends to occur in the middle-aged and elderly because their abdominal walls weaken as they age.
- Femoral hernia: The femoral canal is the path through which the femoral artery, vein and nerve leave the abdominal cavity to enter the thigh. Although normally a tight space, sometimes it becomes large enough to allow abdominal contents (usually intestine) to protrude into the canal. A femoral hernia causes a bulge just below the inguinal crease in roughly the mid-thigh area. Usually occurring in women, femoral hernias are particularly at risk of becoming irreducible (not able to be pushed back into place) and strangulated. Not all hernias that are irreducible are strangulated (have their blood supply cut off), but all hernias that are irreducible need to be evaluated by a health care provider.
- Umbilical hernia: These common hernias (10 – 30 percent) are often noted at birth as a protrusion at the bellybutton (the umbilicus). This is caused when an opening in the abdominal wall, which normally closes before birth, doesn't close completely. If small (less than half an inch), this type of hernia usually closes gradually by age 2. Larger hernias and those that do not close by themselves usually require surgery at 2 to 4 years. Even if the area is closed at birth, umbilical hernias can appear later in life because this spot may remain a weaker place in the abdominal wall. Umbilical hernias can appear later in life or in women who are pregnant or who have given birth (due to the added stress on the area).
- Incisional hernia: Abdominal surgery causes a flaw in the abdominal wall. This flaw can create an area of weakness in which a hernia may develop. This occurs after 2 to 10 percent of all abdominal surgeries, although some people are more at risk. Even after surgical repair, incisional hernias may return.
- Spigelian hernia: This rare hernia occurs along the edge of the rectus abdominus muscle, which is several inches to the side of the middle of the abdomen.
- Obturator hernia: This extremely rare abdominal hernia develops mostly in women. This hernia protrudes from the pelvic cavity through an opening in the pelvic bone (obturator foramen). This will not show any bulge but can act like a bowel obstruction and cause nausea and vomiting. Because of the lack of visible bulging, this hernia is very difficult to diagnose.
- Epigastric hernia: Occurring between the navel and the lower part of the rib cage in the midline of the abdomen, epigastric hernias are composed usually of fatty tissue and rarely contain intestine. Formed in an area of relative weakness of the abdominal wall, these hernias are often painless and unable to be pushed back into the abdomen when first discovered.
Although abdominal hernias can be present at birth, others develop later in life. Some involve pathways formed during fetal development, existing openings in the abdominal cavity, or areas of abdominal-wall weakness.
Any condition that increases the pressure of the abdominal cavity may contribute to the formation or worsening of a hernia. Examples include
- heavy lifting,
- straining during a bowel movement or urination,
- chronic lung disease, and
- fluid in the abdominal cavity.
A family history of hernias can make you more likely to develop a hernia.
Symptoms and signs
The signs and symptoms of a hernia can range from noticing a painless lump to a painful, tender, swollen protrusion of tissue that you are unable to push back into the abdomen (an incarcerated strangulated hernia).
- Reducible hernia
- It may appear as a new lump in the groin or other abdominal area.
- It may ache but is not tender when touched.
- Sometimes pain precedes the discovery of the lump.
- The lump increases in size when standing or when abdominal pressure is increased (such as coughing).
- It may be reduced (pushed back into the abdomen) unless very large.
- It may be an occasionally painful enlargement of a previously reducible hernia that cannot be returned into the abdominal cavity on its own or when you push it.
- Some may be chronic (occur over a long term) without pain.
- An irreducible hernia is also known as an incarcerated hernia.
- It can lead to strangulation.
- Signs and symptoms of bowel obstruction may occur, such as nausea and vomiting.
- Strangulated hernia
- This is an irreducible hernia in which the entrapped intestine has its blood supply cut off.
- Pain is always present, followed quickly by tenderness and sometimes symptoms of bowel obstruction (nausea and vomiting).
- The affected person may appear ill with or without fever.
- This condition is a surgical emergency.
When to seek medical care
All newly discovered hernias or symptoms that suggest you might have a hernia should prompt a visit to the doctor. Hernias, even those that ache, if they are not tender and easy to reduce (push back into the abdomen), are not necessarily surgical emergencies, but all have the potential to become serious. Referral to a surgeon should generally be made so that the need for surgery can be established and the procedure can be performed as an elective surgery and avoid the risk of emergency surgery should your hernia become irreducible or strangulated.
If you find a new, painful, tender and irreducible lump, it's possible you may have an irreducible hernia, and you should have it checked in an emergency setting. If you already have a hernia and it suddenly becomes painful, tender, and irreducible, you should also go to the emergency department. Strangulation (cut off blood supply) of intestine within the hernia sac can lead to gangrenous (dead) bowel in as little as six hours. Not all irreducible hernias are strangulated, but they need to be evaluated.
Care at home
In general, all hernias should be repaired unless severe preexisting medical conditions make surgery unsafe. The possible exception to this is a hernia with a large opening. Trusses and surgical belts or bindings may be helpful in holding back the protrusion of selected hernias when surgery is not possible or must be delayed. However, they should never be used in the case of femoral hernias.
Avoid activities that increase intra-abdominal pressure (lifting, coughing or straining) that may cause the hernia to increase in size.
Treatment of a hernia depends on whether it is reducible or irreducible and possibly strangulated.
In general, all hernias should be repaired to avoid the possibility of future intestinal strangulation. If you have preexisting medical conditions that would make surgery unsafe, your doctor may not repair your hernia but will watch it closely. Rarely, your doctor may advise against surgery because of the special condition of your hernia.
The treatment of every hernia is individualized, and a discussion of the risks and benefits of surgical versus nonsurgical management needs to take place between the doctor and patient.
All acutely irreducible hernias need emergency treatment because of the risk of strangulation. An attempt to reduce (push back) the hernia will generally be made, often with medicine for pain and muscle relaxation. If unsuccessful, emergency surgery is needed. If successful, however, treatment depends on the length of the time that the hernia was irreducible.
Occasionally, the long-term irreducible hernia is not a surgical emergency. These hernias, having passed the test of time without signs of strangulation, may be repaired electively.