The myths of why hands swell while hiking
You’re five miles into a hike with a group of friends. You’ve never been hiking before and it sounded adventurous and fun and a great way to to get out and have fun with friends, enjoy being outside, and relax for a bit. And you’re having a great time with the exception of a weird feeling in your hands. Your wedding ring and watch are getting tight and your skin feels taut. Your arms feel bloated and you look down and sure enough you’ve got big old sausage fingers. Are you dying? Do you need to turn around and race to the hospital? Maybe you have cell service and after you post a quick pic to insta you do a quick WebMD search. It says you have heart failure or this weird thing called thrombosis. Now you’re worried and want to go back so you can do more internet searching before you head to the ER. When you get home you dig deeper in your internet searching and get more specific. Instead of just searching hand swelling, you search had hands swell while hiking and find an Outside Magazine article, where you may learn that you’re suffering from hyponatremia. You find a facebook thread of loads of confident expert internet commenters recommending the cure-all tip of hydration or electrolytes.
But nearly all this information you’ll find is absolutely, jarringly, painfully wrong, so I hope this article becomes the one to top out on the google searches so maybe some people will learn the real answer, and learn a real solution. You don’t have heart failure, you’re not alone, and you don’t need to hydrate.
The real reason your hands are swelling
The reason your fingers are swelling is multifaceted but actually pretty simple. Before I explain I just want to clarify again that you’re fine, it happens to everyone and it’s totally normal and reversible.
The vasculature in your body is just a giant network of leaky plumbing. Imagine your body being a greenhouse with a sprinkler hose with hundreds of little holes running through it. The water that didn’t leave the hose is simply looped back around, much like your veins bring blood back to your heart. That hose brings essential fluid to the plants in that garden. Your vasculature in your arm is very similar to that garden hose. It runs down your arm, releases water into that tissue, and the excess water drains back to be recycled. When you step on that garden hose, aka put backpack straps on your upper arms, it increases pressure and increases the rate of that fluid shooting out of the uncountable tiny holes in the hose.
This is one cause of the swelling. Another cause is that the backpack straps essentially dam up the return flow like putting a wall in the trough. Now imagine there’s a drainage trough alongside the garden which returns the excess water from the soil to a pool where it can be recycled back into the hose to continue watering the plants. That is comparable to something in your body called the lymphatic system, which, much like a drainage trough, is a series of ducts which drain extra water in that extravascular space and recycles it back to your heart. By clamping down on those lymphatic ducts with backpack straps, it dams the trough, preventing fluid from draining from that extravascular space.
There’s another thing at play though. And if you’ve ever hiked with trekking poles while still wearing a hand swelling inducing backpack, you may be able to reason through that there has to be something else going on by the fact that trekking poles totally fix the problem. When we hike with trekking poles, even if we have the heaviest of backpack straps constricting our upper arms and shoulders, we don’t experience the swelling really at all. So it can’t just be the backpack straps causing it, especially since some people have this issue without wearing a backpack at all.
Something interesting about the cardiovascular system is that the blood pumping through our arteries, the big pulsating vessels we feel when we check our pulse, are almost entirely pumped by the heart. The heart contracts, much like squeezing a balloon full of water, and blood comes out of the hole. However, when the blood is returning back to the heart to be cycled again the blood is to a significant degree pumped because of contracting muscles in our limbs. They have one way valves in them so when we contract a muscle that is wrapped around a vein, it pumps the blood forward. And when that contraction ceases, the blood is unable to flow backwards. That repetitive contraction of our legs and arms pushes the blood forward, back to our heart. The reason we don’t experience edema in our legs on long hikes isn’t simply because of no backpack straps compressing the vasculature, but mostly because of our constantly contracting and relaxing leg muscles. When we use trekking poles, we continually contract the muscles in our arms and push that blood back toward the heart, preventing pooling by overcoming those barriers created by the backpack straps.
Additionally the trekking poles also likely benefit the swelling by shifting our shoulders frequently, releasing the pressure of the backpack straps on the upper arms, even if just for a second at a time. There could be an electrolyte component to it, but I find it exceedingly unlikely that this is a primary cause because the swelling would be consistent throughout the body, including the face, and I’ve only ever experienced and heard of people having swelling in their arms. Additionally, it takes a tremendous blow to knock the body’s electrolyte balance off. The body is very good at maintaining electrolytes in the blood in a very narrow range of values and the hyponatremia it would take to cause swelling would not only cause significant additional symptoms like nausea, vomiting, confusion, seizures, death, etc., but it’d also take a significant blow or underlying medical disorder to cause it.
Additionally, if dehydration were the issue, once again the swelling wouldn’t be isolated to the arms, and it’s also very uncommon for water to collect in the extravascular space when there is an overall deficit of water in the body. It can definitely happen but it’s rare and comparable to a dry paper towel sitting in a pool of water. The paper towel is going to soak up the water like our body is going to soak up that swelling.
Also, definitely not gravity as the primary culprit. If that were the case our legs which are much longer and have a much harder battle against gravity back to the heart so if gravity were the culprit our feet would be as thick as elephant stumps. And definitely not altitude: just go for a hike at sea level; it stills happens and there’s no reasonable mechanism. And just for completeness sake, it’s not temperature’s fault either. Once again, if that were the case, there’s no reasonable explanation for why it would be isolated to the hands and arms.
How to keep your hands from swelling
Now that I’ve explained the pathophysiology of hand swelling while hiking, I have a couple solutions. My first recommendation is using trekking poles, for so many reasons in addition to totally preventing the hand swelling. They help prevent injuries, make hiking easier, faster, and enable you to bounce down gnarly trails like a mountain goat. You’ll look dumb to everyone who has never used them but hey you already look dumb to everyone back at home relaxing on their sofas.
I highly recommend the Black Diamond Distance Z trekking poles.
If you absolutely refuse to use trekking poles or simply don’t hike often enough to drop the dough, I recommend you do some exercises while hiking. Take your hands and put your thumbs on your backpack straps and lift them off your shoulders. This will contract your muscles as well as relieve the pressure. It’ll also elevate your forearms to help promote some of that return flow. If you want to look extra special you could wave your hands in the air like you just don’t care, maybe show off your guns and flex a little for the single does prancing through the forest. If you want to look sooooper cool you could whip out the compression sleeves but I can’t imagine that helping much.
Or just get trekking poles and accept your fate that it’s impossible to look cool while hiking.
35 thoughts on “Why your hands swell while hiking: the real reason”
I agree with you in the fact that the Lymphatic System is involved and edema is occurring when hands and fingers puff up. I also believe that the use of trekking poles helps as I’ve seen this anecdotally with my wife. Again, the lymph system is activated through the simple movement of the arms, thereby creating better circulation of the lymphatic system.
I’m not sure I buy into the backpack straps creating a tourniquet effect and contributing to the problem. My wife had problems many years ago just day hiking with no pack(sans poles) and used to regularly have swelling occur. (Again anecdotal) Do you have any research or studies that support the claim of backpacks contributing to the problem? If there is that much pressure occurring due to the backpack, and a waist belt is being utilized it seems to me the pack would not be fitted correctly.
I agree, hydration, electrolyte loss, etc is not contributing to the problem. It’s definitely seems to be a circulatory issue, likely confined to lymphatic circulation. If it was venous or arterial then you’d have temperature and color change in the extremities.
Good article and food for thought!
Thanks for your comment Matthew! I’ve never seen any research so it’s just a mechanism at best but it’s a realistic mechanism and the only reasonable one I’ve seen that’s been proposed. It’s definitely hard to globally diagnose likely hundreds of thousands if not millions of people with some sort of transient thoracic outlet syndrome but I figured it’s better than the garbage mechanisms I’d seen proposed online. I’m with you though that it can’t be isolated to simple compression of the backpack straps. I think it’s very likely largely due to lack of muscular contraction in addition to the compression or as an isolated mechanism itself. Once again, thanks for your feedback and I’m glad you liked the article!
Good on you for thinking outside the box! Thanks for the reply.
30 yrs obcessed w/ lymphatics – You are 100% correct. It takes very little pressure to impede lymph drainage, as the vessels are close to the surface and more like overcooked rice noodles than a firm rubber hose. It doesn’t take much to impact them. For the research, look to lymphedema after breast cancer and the effect of bra straps, adhesions, scar tissue – even the armpit crease itself. A simple check is to look in the mirror naked right after you take off the pack, the bra, the underwear, the waistbands, the socks – if it leaves a red mark or indentation of the skin, it slowed your lymphatic flow. Over time, this creates a ‘couch-on-the-carpet’ effect of compressed, fibrotic tissue that perma-smooshes the pathways needed for these super-squishy lymph vessel garden hoses to be allowed to flow properly. Re-fluff compressed tissue anywhere it gets smooshed, crinked, pulled tight over a bone or joint, scarred, dried up or constricted by perma-tight muscles due to biomechanical imbalanced that restrict FULL range of motion. By that I don’t mean accepted adult ‘normal’ ROM – more like play follow-the leader with a small child and do what they do type of motion. They twist and bend and do weird things that puts their tissues through full squeeze-release cycles that make the stuck tissue juicy, the pathways re-lofted, and the lymph flowing. If you need compression, your hoses aren’t flowing somewhere along the line… far better to address that issue from a ‘clear the plumbing’ perspective than to increase distal pressure to compensate. Injuries, however, need compression, the drainage pathways addressed, and the local area worked like playdough for ~2.5 years in order to heal with top-quality elastic replacements instead of the bondo of scar tissue.
I’m new to hiking. I bought an Osprey Atmos AG 65. I’ve occasionally loaded it up with stuff just to practice using it.
Today I loaded it with Just under 30lbs.
Initially I noticed my hands swelling and figured it was the backpack straps.
At about a half hour mark (luckily as i was arriving home), I noticed my left arm was numb. The blood came back as soon as I took the backpack off.
I wasn’t using trekking poles. Don’t own any. Never understood the appeal. But if this article is for real, I might just try them.
I also suspect the centrifugal force of your swinging arms has something to do with it – all that force pushing the fluid outward, acting against the not-so-active lymphatic system in the arms. If you want to test the relative contribution of centrifugal force vs the other processes you mentioned, you could try hiking with your arms fixed at your sides, rather than swinging them 🙂
Lolol that would be amazing.
I look friggin’ AWESOME with my trekking poles 🙂
Lolol keep telling yourself that 😉
Nice to hear that am fine and it happens to most people. I have never encountered such a comprehensive explanation on why my fingers swell on a hike. Just well written. Thanks for sharing.
I wear tight fitting gloves while hiking. They protect my hands while scrambling up slopes or in case I trip and they keep the fluids from building up in my hands.
Can tight fitting gloves really help you from swelling. I would really like to know.
Yup. Same mechanism as compression socks.
My hands routinely swell even when going on long walks in my neighborhood. In my case it has nothing to do with wearing a backpack since it only occurs when I’m NOT wearing one. In fact, my husband and I just completed an 800-mile section hike of the Appalachian Trail this summer and my hands never swelled once in all that time (and I was wearing a fully loaded pack for 10-12 hours a day). However, by reading your article I have stumbled on the key: trekking poles. I only use my poles when I’m on the trail (as opposed to strolling around the neighborhood), and that must be what keeps my hands from swelling. By the way, I agree with the poster who said your backpack straps shouldn’t be putting that kind of pressure on your shoulders and arms. If they are, you are either wearing the wrong pack or you haven’t loaded the weight correctly.
And there’s more: I walk for an hour in the house, no backpack, every day. Within about 20-30 minutes, my hands and feet start swelling a little. This is part of my anti-asthma breathing exercise, and the effect is expected. It is associated with keeping the mouth closed while breathing during the exercise and experiencing vasodilation. Totally normal, and it goes away after the exercise. In fact, the bit of swelling tells me that I’m doing the breathing properly while walking.
This happens to me when I’m walking for exercise, so it’s not a backpack issue for me. I usually try to walk with my elbows more bent and my hands up, seems to help some. I’ll try flexing and extending and see if that helps more.
This is cool! I had never heard it explained this way, thanks for sharing Grayson!
Holding something in your hands that’s about the size of a treking pole handle or a roll of quarters has proven to help prevent swelling for speed walkers runners and hikers. Just gripping something with an occasional squeeze does the trick for me. I only use poles when there’s tricky steep downhill’s to encounter.
Its super nice to know that I am not a freak of nature and that my hands swell due to swinging them on walks.
Thanks for sharing great tips.
My hands swell the most when I first begin walking/hiking again after a layoff. As I get fitter, the swellings diminish and at some point no longer occur. I live in South Africa where many people walk significant km each day simply going to and from work. None of them have hand swelling. I attribute it to simple immobility of hands and fingers when walking while unfit.
This doesn’t happen to me so much when hiking, even when I carried a very large and heavy backpack for a few weeks daily, though I was using poles. I do find I get this when I sleep in a tent lately though and it’s been bothering me a lot. I’m not sure if it has something to do with my mat. I don’t remember it happening with my old mat, yet my new one is a more expensive and more padded thermarest. Any ideas?
Hmmm I can’t think of why that might be happening. Are you a pretty solid sleeper? You could be getting some venous stasis just from sleeping soundly. We typically adjust throughout the night which helps move some blood and shift pressure from our muscles.
I’ve actually never experienced it while hiking with a backpack, however it happens to me several times a week while on the walking trail at the park (no backpack).
Huh. I’ve had a lot of people say this. It must just be the venous stasis in that case independent of the compression.
Thanks for your post. I get this but it doesn’t matter if it’s a fanny back or backpack. If I swing my arms more it helps alleviate it. But sometimes I forget until I get sausage fingers. I like the idea of trekking poles, but I’ve found it interferes with the step count of my Fitbit. So a trade off there. If it’s a short hike, I just need to swing my arms.
Thanks for the info and article, Very helpfull !
I specifically searched for sausage fingers after hiking 11 miles in Wyoming today. I regularly run 1/2 and full marathons and never get sausage fingers from that but I do while hiking (without trekking poles/ guess I’ll have to try them) .
I know all too well about hyponatremia from running and instructors drilling into us “hydrate hydrate hydrate” Rarely has anyone died in a marathon from dehydration that I know of, but I did get sick once from drinking too much water.
I’m agreeing with you that pack straps contribute to the swelling but also that the constant downward (mostly muscle less) swinging motion is probably a big factor too.
Thanks again for your expert insight !
I laughed so hard because I just had this experience! I recently attempted the 17 mile Bright Angel Trail to the Colorado River and back at Grand Canyon South Rim. 3 miles in my hands were a bit swollen, felt fine otherwise so I kept going. Quite a ways further, my arms were so swollen (my veins were bulging) I thought they were going to explode. Totally thought I was going to have a heart attack and die….completely freaked out…felt absolutely terrible. After a break I continued the hike, but walked with my hands on my head. This did the trick, the swelling subsided and I felt even better than when I had started the hike.
Didn’t really feel any other symptoms of altitude sickness so I figured it must be something related to circulation. Thanks so much for this post!
For sure! I’m glad you enjoyed the post.
I have noticed that carrying an umbrella fixes hikers fat fingers, as long as I switch hands regularly. I had put it down to gravity, but now I have read this, reduced lymphatic drainage makes a lot of sense. I need to aquire hiking poles!
Great article! Thanks, finally confirmed my suspicion on what was going on, when we hiked long distance in the alps my hands were doing just fine (trekking poles!) but as soon as I go on a day hike, my hands swell up by lunch time! I choose the “ocationaly waving hands up in the air like a madman” method, works like a charm 🙂
I experience this too only after a long winter like this year in Colorado and I contribute it to not being in shape because as soon as I start hiking more regularly the swelling does not occur. It happened to me last week on my first long and steep hike above 6500 ft elevation. I did not wear a backpack, but i also did not try trekking poles. I will give that a try on my next hike, as a matter of fact i own a single trekking pole and will make sure i use it with one arm only so i have something to compare it too. Not a bad theory though 🙂
On your Appalachian through hike, did you start north or south and when? Why no tarp, bivy or tent? Why no cooking gear or was it all energy type bars, etc.? Why only 2 – 20 to 24 oz bottles? How did you manage w/o H2O for the long sections w/o ? How many miles did you go on avg./day? Surely, your pack alone weighed 8 to 12 oz.. Was it included in your gear weight? I wish I had direct access to you for the many questions I have. Having invented a running pack, weighing 4.9 oz that eliminates 5 to 8 bio-mechanical inefficiencies of the backpack and 4 of the bio-mechanical inefficiencies of the vestpack that you wore, I’m curious about your accomplishment. What was your running frequency vs walk at what approx. speeds of each? Hoping to hear from you.
Hey Stuart. That’s a lot of questions! Sorry for the late response. Started in maine. had a tarp. no cooking. didnt need more water. the at is loaded with water. cant remember my avg. pack was light and included in gear weight. walked 90+%. walked around 3.5-4 mph. ran slightly faster than that but not enough to be worth it. I hope this helps. Message me again if you have more questions and I’ll email you my phone number so we can chat.
This happens to me with one pack, almost imediatly, and with another (albeit also less weight) after a good bit. I had asked about this on a a hikers enthusiasts FB page and got no credible responses. what you are saying makes sense, as I know that using my thumbs and pushing up on the straps did make a positive change. I was thinking that I needed to change to a pack that was akin to a football players shoulder pads (never heard of that though! Thanks for the comment!