The Ins and Outs of Hernias by Dr. Mangum, D.O., Internal Medicine

Question:

What is the timing for how long hernias develop? Do people notice it at work because it came on acutely, or is it something that has been developing for a long time? When do you first see a symptomatic hernia come on? Is it an acute thing, or is it something that has been developing for a long time?

Answer:

There is a spectrum answer to that. There are a wide range of ways people present. From my experience, individuals who say, ‘I just noticed this one day out of the blue,’ often have hernias that were already present on imaging for many years, sometimes decades, but were not symptomatic. With rare exception, when I have the opportunity to review earlier imaging, I have seen this pattern repeatedly of a hernia being visualized years earlier.

I think the majority of hernias start off years, if not decades, before they develop into a symptom. That opening in the connective tissue may have been present since birth, and at some point, it stretches out big enough that we start to get a little symptom, typically a little fat pushing through. They will not notice that until it either pops out and they feel it, or they are taking a shower, and they look down and they see it.

When they have a symptom or a sign, a sign being a bulge and a symptom being discomfort, versus how long it has been present, are often quite different. But narrowing it down to when it first started is a challenge.

Question:

In an injury case where they are alleging an acute incident at work, how would you weigh if an acute intra-abdominal increase, like a heavy load, caused the hernia? A physician will say, ‘They were lifting 200 pounds, felt a pop, and then there’s a bulge there.’ How do you rebut that in an IME?

Answer:

I like to point out that people can lift 200 pounds, or they can lift 20 pounds. They can just sneeze. It does not necessarily take that much weight or effort to cause something to pop out. But I always put in my reports that if something pops out, I will comment that a bulge is a sign. And if they feel discomfort, I will explain pain or discomfort is a symptom. But signs and symptoms are distinctly different to the pathology.

The pathology is that defect and opening. You would not have a hernia pop out if you didn’t have an opening. I try to make it clear that I would not deny someone developing a symptomatic bulge or sensation when they are at work, but that is not the same as what the problem or pathology is.

Although they push the bulge back in during surgery, they are not fixing the bulge itself. They are fixing the defect by closing the opening and adding mesh to prevent it from popping out again. Lifting can cause someone to have a sign or symptom. It is just not the same as what the problem is.

Question:

What is the difference between the temporal onset of symptoms rather than the actual cause?

Answer:

The onset of symptoms, whether they felt it with one lift, all day long lifting, or the next morning or whatever their claim is going to be, is different from the cause and the pathology. Does lifting cause that? And no, it cannot cause the pathology.

I have seen cases where someone had a belly button hernia. I have had cases where someone has had it known for over a decade, and then they say one day it got bigger because they lifted at work, and somehow that is considered a material contributing cause to needing treatment. And it gets accepted because it was a single “injury’ event.

I understand why it happens, but I just do not think that is the right conclusion to that kind of problem.

Question:

Why do various IME doctors, general surgeons, and internists have different opinions on causation of hernia, and most say they are work-related?

Answer:

It has just been a widely held belief in the general public, including among physicians before they became doctors, that lifting causes hernias. I grew up understanding that when you lift and strain, you should not hold your breath because you might “pop a hernia.” I remember a doctor telling me that when I was a teenager.

When we went through medical school, nobody ever talked about this. They told us about hernias and how to diagnose them. We learned about how to do surgery, but we never went down this path of, “What exactly causes them?”

When I first started doing IME work 30+ years ago, and I came across my first few hernia cases, I had not really thought about it. I had to research and dive in and started really looking into it. If you don’t do that, then you are going to continue with what you thought growing up and throughout your life, that lifting causes hernias.

One of the main issues is the idea of intra-abdominal pressure. You will hear that lifting and increased abdominal pressure causes hernias. But if that were true, we would expect people who generate the highest abdominal pressures to have more hernias. That has been studied. Weightlifters, people doing wrestling, martial arts, and other physical activities generate very high pressures, and they do not have increased rates of hernias.

The pressures that have been measured in these activities range between about 2 to 3.6 pounds per square inch. Your car tire has 40 PSI. Your bike tire has 100 PSI. There’s very little abdominal pressure because the pressure can only occur when we take a deep breath and we crunch our abdomen. It really cannot build any other way. The pressures we can generate are quite minimal.

The pressure is also occurring within the abdomen and pelvis when we lift, but that is against the peritoneum. The peritoneum is a very strong, thick connective tissue. The tissue we’re talking about for groin hernias is spider-web thin, but it is stretchy and flexible. It does not tear with injury. It just separates gradually or is open from developmental reasons.

Another analogy I use is pregnancy. If increased intra-abdominal pressure caused hernias, what about women who have a full-term pregnancy and deliver vaginally? In their last trimester, they are going to have significantly higher intra-abdominal pressure. During labor and delivery, it is going to be dramatically higher. Yet, we do not we see inguinal hernias in women or in this subset of women. Some women get hernias, but not nearly to the same level as men. That is because intra-abdominal pressure does not injure the connective tissue.

I think it is a combination of bias and just how we initially thought this happened and not taking the time to go through the data to understand if it makes sense.

Question:

Is a hernia an injury or is it just a finding or medical condition?

Answer:

The answer is it is a finding and there is not an injury that causes it.

Dr. Daniel Mangum, D.O., is an internal medicine specialist in Portland, Oregon and has over 36 years of experience in the medical field. He received his medical degree from College of Osteopathic Medicine of the Pacific and has been in practice for more than 20 years.

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A Previous “Ask the Doctor” Response
In our previous “Ask the Doctor” blog, Dr.Ilias-Khan, cardiologist, explains how stressors relate to cardiac events in the workplace.