Last reviewed and revised February 27, 2013
My father used to ask me and my siblings to help him lift anything heavy, saying he didn't want to get a hernia. But is there really a link between lifting or straining and hernias or is it just another medical myth, passed down through generations of medical education and folk wisdom, based on little more than intuition?
First it's important to be familiar with the various types and causes of hernias:
It's understandable how the connection between lifting and hernias got started, but just because it's been around a long time doesn't mean it's true.
This is a good example of how cause and association can be confused. A person with an abdominal hernia, for example, might notice it for the first time after lifting something heavy. That's because lifting increases pressure in the abdomen and this additional pressure could encourage the abdominal contents to find their way through a weakened part of the lining. But that doesn't mean that lifting caused the hernia.
Commonly used surgical textbooks as well as reliable online medical websites and medical journals I checked all stop short of saying hernias are caused by strenuous lifting. It's more likely, they say, that lifting made the problem more obvious and that the true cause is a pre-existing weakness in the lining of the abdominal wall.
In fact, most people who lift heavy objects never develop a hernia (at least not one they notice or that needs attention; small ones might be present much more commonly than is realized).
So if there's no conclusive evidence linking lifting or physical exertion with the development of hernias, what causes them?
In many, or perhaps most, hernia cases, the true cause is unknown. In others, such as inguinal hernias, the cause is a congenital or developmental factor, meaning that the weakening occurred before birth during fetal development. (A hernia in a young person is generally assumed to be due to a congenital or developmental factor while an older person's hernia is considered "acquired." But in most cases, the true cause unknown regardless of the person's age.)
Sometimes, hernias run in families, suggesting this weakness in the lining of the abdomen is genetic.
The truth is that exertion may be less important than commonly believed. Less than 10% of inguinal hernia sufferers report a physically strenuous event just before diagnosis. (An exception is Workmen's Compensation cases, where the report of exertion just prior to hernia diagnosis is much higher.) Another finding: up to 10% of the population have "spontaneous" hernias of the abdominal wall meaning that there was no apparent heavy lifting or straining that preceded the diagnosis.
People with an abdominal hernia should probably avoid stress to the weakened area by avoiding heavy lifting or similarly strenuous activities that increase abdominal pressure. A small weakness or tear can enlarge with increased abdominal pressure. Other means of increasing abdominal pressure can do the same thing — this includes pregnancy, straining to pass a bowel movement or to urinate, obesity, or chronic cough. For these reasons, losing weight and taking measures to avoid constipation are routinely recommended for people who have had any of these abdominal hernias.
If lifting actually caused a significant portion of all abdominal hernias, we ought to discourage lifting whether at work, around the house or for recreation. After all, hernia repair is the most common operation in this country: more than 700,000 inguinal hernia repairs are performed each year. But many people lift on a regular basis without developing a hernia, so it would be premature to restrict this common activity.
Hernias are usually not dangerous, however, their complications can be. The most feared one is that a loop of intestine will get stuck ("incarcerated") through the tear or hole in the lining of the abdomen, causing pain and blockage of the intestine (called an obstruction). Eventually, the blood supply to that portion of the intestine may be interrupted which can lead to tissue death a serious situation. On the other hand, many hernias never cause such problems, especially if they can be "reduced," that is, if a protruding loop of bowel can easily be pushed back into normal position there's only a small chance it will soon become stuck.
Conventional wisdom has long dictated that once diagnosed, a person with an abdominal hernia should have it repaired (unless the surgery is considered too risky due to other medical problems). However, a new study suggests that men with inguinal hernias who didn't have surgery did just as well over an average of 4 and a half years as those who had surgery. It remains unclear whether surgery will eventually be necessary for most abdominal hernias. Having cared for several patients who turned down surgery and did just fine over a prolonged period of time, it seems likely that some people can safely defer surgery.
If you have a hernia, it might be a good idea to get help before lifting anything heavy. But if you've never had a hernia and are worried you might develop one from lifting, there's little reason to be concerned. You might want to ask for help to protect your back or prevent other injuries, but not because you'll actually prevent the development of a hernia.
Robert H. Shmerling, M.D., is associate physician at Beth Israel Deaconess Medical Center and associate professor at Harvard Medical School. He has been a practicing rheumatologist for over 20 years at Beth Israel Deaconess Medical Center. He is an active teacher in the Internal Medicine Residency Program, serving as the Robinson Firm Chief. He is also a teacher in the Rheumatology Fellowship Program.