This Illness Could End Your Hike or Your Life, and You’ve Never Even Heard of It

Ed. note: This article is for informational purposes only and is not intended as medical advice. This article does not substitute for professional diagnosis, treatment, or advice. Always consult a qualified healthcare provider with any questions you may have regarding a medical condition.

When planning for a thru-hike, there are so many things to consider. Many people find it comforting to consider the worst-case scenarios. Working through these problems in your mind beforehand may make them easier to overcome if the situation ever arises.

If you are planning for a thru-hike you likely have heard of norovirus, giardia, or tendonitis. Perhaps you’ve researched major gear failures and studied how to avoid blisters heat stroke, frostbite, dehydration, etc. All problems you might face while thru-hiking.

But what would you say if I told you there was an even more dangerous ailment that could plague your thru-hike? Something that could end your thru-hike, or even your life, if you didn’t diagnose it soon enough. Would you be surprised to learn that such an illness exists — and that you’ve likely never even heard of it? 

Back in June I set out on the 3,000-mile Continental Divide Trail. This trail stretches from Canada to Mexico and goes across Montana, Idaho, Wyoming, Colorado, and New Mexico. I decided to hike southbound in hopes of avoiding deep snow in Colorado’s San Juans.

Just like any other thru-hike, I considered and planned for all the pitfalls I mentioned above. I’ve gotten norovirus on trail before and dealt with tendonitis. I’ve also ridden the risky edge of hypothermia, dehydration, and heat stroke. Over the last few years, I’ve hiked 10,000+ miles across the United States and Canada.

If you had asked me what my biggest concern was when embarking on my latest thru-hike, I probably would have told you tendonitis or something similar. But over the last few weeks, I have gained a new worst fear when it comes to thru-hiking.

And its name is rhabdomyolysis.

Laying in bed in town resting. My whole tramily got sick, so we took a couple days off to be sure that everyone felt better before continuing.

While hiking through Montana’s Bob Marshall Wilderness on the CDT, I ran into a friend of mine that I hadn’t seen since the Appalachian Trail. He was dealing with what he thought were norovirus symptoms. So I brought him some Pepto and hiked with him for the remainder of the day until we got closer to town.

After a day or two in town, he felt a whole lot better and got back out on the trail. But over the following week, he would continue experiencing an array of symptoms, eventually leading to a diagnosis of rhabdomyolysis. A life-threatening illness I had never even heard of. Something that I would have been worried about over my entire thru-hiking career if I’d known what it was.

Rhabdomyolysis is a condition caused by direct or indirect injury to your muscles. When such an injury occurs, it causes muscle tissue to die and be released into your bloodstream. The result of this can be complications such as kidney failure, sepsis, or even death. Many things can cause rhabdo, from medications to traumatic injuries. For the sake of this article, I will focus on two common triggers that would be most likely to result from thru-hiking.

What causes rhabdomyolysis?

Muscle strain: Extreme muscle strain is a common cause of rhabdo. Men with a BMI over 30 are especially at risk of getting rhabdo from muscle strain. That’s because they have more muscle mass to be broken down. That said, rhabdo also occurs in extreme athletes. So anyone straining their muscles to extreme excess could be at risk, BMI aside.

High body temp: Rhabdo can also be caused by very high body temperature or heat stroke. People who work outside are at risk for this reason, as are, of course, thru-hikers who stay out day and night.

In the last couple of weeks alone, I’ve been hiking through a constant heat wave, with temperatures in the mid-90s daily. During that time I have continued hiking 25-30 miles per day. And hundreds, if not thousands, of other hikers are on trail across the country exerting themselves under similar conditions.

Hiding in the shade after hiking in 95-degree temperatures all day. We were careful to take breaks and drink a lot of water to avoid heat stroke.

Both extreme muscle strain and high body temperature/heat stroke are common daily occurrences while thru-hiking. Which puts thru-hikers at particularly high risk for developing rhabdo. We are straining our muscles to the extreme every single day. Especially at the start of a thru-hike.

Feeling exhausted after road walking in the hot sun for hours. Know your limits, and when to take breaks in the shade!

What are the symptoms of rhabdo?

Just as many things can cause rhabdo, the symptoms can also vary widely. But there are some main symptoms to look out for and warning signs to remember. The most common rhabdo symptoms are:

1. Muscle pain in the shoulders, thighs, and lower back
2. Muscle weakness — trouble moving your arms or legs
3. Decreased urination, or in extreme cases dark red or brown urine

Other common symptoms that may occur early on and be a warning sign of rhabdo are dehydration, fever, confusion, rapid heart rate, nausea, vomiting, or abdominal pain. While these symptoms are common to many different conditions, you should still pay attention to these important indicators.

If you are experiencing any of those “milder” symptoms, that would be a sign that something serious is happening within your body. Even if it isn’t rhabdo, something is clearly wrong.

A beautiful morning on trail. Pushing yourself too hard could result in the premature end of your thru-hike. Rest and take care of yourself so that you can keep enjoying the wonders of the trail.

What should you do if you experience any of these symptoms on trail?

The first step is to acknowledge what is happening. When you are thru-hiking, one of the most important tools you have is the ability to listen to your body. If you begin feeling nauseous, dehydrated, etc., do not ignore those feelings. Acknowledge that something isn’t right, and do the best you can depending on your circumstances.

If you are far from the nearest town, start by messaging a friend or family member so they know what is going on.

Similarly, let other hikers know what’s going on. Rhabdo isn’t contagious, but making other hikers aware of your symptoms will let them know to look out for you and monitor you for further changes. If possible, hike and camp with others so that support is near at hand.

As soon as possible, get to town and seek medical attention. You never know when an emergency could arise on trail. It would be wise to carry any extra half day’s or day’s worth of food in case you have to hike slower and take more time to get to town. This can happen for a variety of reasons, not just rhabdo. 

The trail is always going to be there! Taking a day or two off of hiking to prolong your hike might just be worth it.

If your symptoms don’t seem “that bad,” it can be easy to ignore these signs. Many “strong” hikers would potentially push past such warning signs and assume that they will feel better soon. Consider taking a day off trail to rest. If that’s not feasible, then maybe do a shorter day to see how you feel.

Stay hydrated, fuel your body with food and nutrients, and avoid hiking in extreme heat. But if your symptoms persist, it’s important to respond accordingly. Rhabdomyolysis is life-threatening.

While this condition is rare, affecting about 25,000 people in the US annually, thru-hiking places you at a higher risk. High-intensity exercise, dehydration, and overheating are all much more common among thru-hikers than the general population. And those are some of the main causes of rhabdo.

Thru-hikers should be particularly cautious of this toward the start of their hikes. Beginning regular, high-intensity exercise without allowing your muscles time to heal is a major potential cause of rhabdo. Sound familiar? That’s exactly how most people begin their thru-hikes.

Should you be living in fear or rhabdo or foregoing your hiking plans to avoid getting it? No, but knowing the symptoms and how to respond to them can only help.

Hiking through an exposed burn area. On days like this, it’s important to hydrate and take breaks in shade when you can.

My friend on the CDT was diagnosed with rhabdo just a couple of weeks ago. I saw him early on in the development and he seemed to be doing alright at that point. At the time, he might actually have had norovirus, as he suspected. It’s possible that after dealing with noro for days he became dehydrated and malnourished. Then in the coming days, he hiked big miles through a heat wave, exposing himself to potential heat stroke. All of these factors, combined with extreme muscle strain, could have brought on his rhabdomyolysis.

Whatever the cause, the end result was that he nearly went septic on trail and could have had major complications if he hadn’t made it to a hospital. Since then he has returned home to rest and heal, possibly ending his thru-hike altogether.

The best-case scenario for rhabdo is diagnosing it early and having to take some time off trail. The worst-case scenarios are major kidney damage, sepsis, and possibly death if the condition goes undiagnosed. Even minor cases of rhabdo can result in long-term side effects as well. And once you’ve had rhabdo once, you’re more likely to develop it again.

Major Takeaways

Admiring a cute deer while in the town of Lincoln. We took a day off to rest and enjoy the 4th of July.

So why is it important to be educated on rhabdo, what it is, and the symptoms? Because once you know about it, you can make informed decisions. Before knowing about rhabdo, I truly thought that the worst thing that could happen if I pushed too hard on trail would be tendonitis or strain something. If I didn’t eat enough I might get a bit malnourished.

Never before did I think that overexertion could cause my body to begin breaking down muscle, which in effect would poison my bloodstream. Even after thru-hiking for years and thousands of miles, I had never heard of such a thing.

I’m someone who likes to know all of these worst-case scenarios so that I can make informed decisions about my health and safety. I love thru-hiking and I would love to keep doing it! Which isn’t going to happen if I’m dead or have permanent medical complications. Hence why I’ve taken some time to educate myself about this condition.

In my opinion, the biggest lesson here is to listen to your body! My friend on the CDT this year saw the warning signs. He was overexerting himself and running himself down, but he kept going, hoping that in time his body would bounce back.

When your body begins revolting against you on trail, you need to listen to it. It’s almost always trying to tell you something. Your intuition is the most important thing you have.

Give yourself time to rest and heal, and if that isn’t enough, it’s time to go to an urgent care or a hospital. Generally, most thru-hikers are in great shape and feel good — aches and pains notwithstanding — most of the time. If all of a sudden you feel terrible and are experiencing various symptoms, then something is probably wrong. Don’t ignore that. If you do, you could truly be putting your life at risk.