Why Do My Hands Swell When I Hike?

One of the most common but rarely-discussed ailments out on the hiking trail is a mysterious condition where hikers’ hands will swell up, causing rings and watches to feel incredibly restrictive and panic to possibly set in upon afflicted hikers. There’s a lot of misinformation about hand swelling on the hiking trail and the simple truth of the matter is that it’s impossible to definitively diagnose the hundreds of thousands or possibly millions of people whose hands swell while they’re out hiking. 

A common culprit is a low-sodium concentration in the bloodstream, which medical professionals have named hyponatremia. There are many causes of hyponatremia but there may not be any sign of hyponatremia in those who actually have it. It’s possible that the sodium level is low but not low enough to warrant the signs of a more extreme case, which could range from headaches and nausea and the lower end to confusion, seizures, or a coma in the most severe cases. 


Man lying down in a field.

If you notice swelling on your hands, try to take a rest to see if it subsides.


It’s dangerous and not realistic to write with any kind of certainty that if someone sees that they have swollen hands on the hiking trail that they absolutely aren’t experiencing any symptoms of hyponatremia. Here’s what we can say with a bit more confidence: hyponatremia can be extremely serious and requires immediate medical attention, but be that as it may, it’s usually endurance athletes who drink too much water during an incredibly strenuous marathon that see their bloodstream sodium level get so diluted that they need medical attention. For the vast majority of people who are just out for a hike, it’s very, very unlikely that they have consumed enough water to dilute the sodium level in their bloodstream and cause hyponatremia. 

What is far more likely the case in almost any scenario is that a hiker’s blood vessels are simply responding to the demand for more energy from the rest of the body with vasodilation, or an expansion of the blood vessels. This is caused by hiking, which is after all an aerobic and taxing activity. The particular mechanisms in the body that cause this are fairly simple to explain and there are a few easy things hikers can do in the middle of their trek to try and reduce the swelling or get it to subside. 

There is also a theory that the excess blood and fluid not absorbed by tissues in the arm when it is pumped from the heart must go back to the heart somehow to be redistributed. However, if there is some cutoff at the arms for some reason, then the blood cannot reach the heart and pools in the extremities. Further aspects of this theory deal with why swelling doesn’t ever seem to occur in the feet.

Read on for a comprehensive look at hand swelling and some of the medical knowledge out there regarding hand swelling on the hiking trail. Bear in mind that this article should not take the place of professional medical advice or medical treatment. 


Symptoms of hand swelling

For clarity’s sake, the problem we’re discussing in this article is a relatively sudden onset of swollen hands. Many hikers don’t notice unless they are wearing a watch or rings that start to feel tight and uncomfortable on their swollen fingers. These fat fingers, or “sausage fingers,” are often a cause of great concern to hikers who have never experienced it before or who cannot figure out whether it’s an anomaly or a symptom of possibly serious medical conditions such as hyponatremia, heart failure, high blood pressure, or something less serious like an electrolyte imbalance. 

Thanks to online medical websites, many hikers who are given to spats of hypochondria from time to time often take symptoms of something completely harmless as possible symptoms of life-threatening diseases. We can’t emphasize enough that there’s no guarantee that hand swelling indicates a serious medical problem. For that matter, though, hand swelling is certainly no guarantee itself that you are free of all medical problems. Odds are very good that fat fingers from hand swelling are indicative of a functioning circulatory system. Hand swelling subsides readily after the hike for the majority of hikers. 


What are some common causes?

Expert-answers regarding the cause of hand swelling abound on forums and websites on the internet. Some say it has to do with sodium levels and others mention electrolyte imbalances, water retention, or high blood pressure. Let’s take a look at some of those possibilities and examine whether there’s good reason for hikers with swollen hands to suspect themselves symptomatic of any of them.


If you’re hiking with a partner, you can have them give you a hand massage to help increase blood flow.


Sodium levels

Your blood sodium level should be somewhere between 135 and 145 milliequivalents per liter (mEq/L). A sodium level below 135 mEq/L can indicate hyponatremia. Sodium helps regulate water in and around your body’s cells. It’s an electrolyte and has to do with water retention to some degree. If the sodium level in your bloodstream is diluted, your cells can begin to fill up with water, which can cause serious medical issues.

There are several chronic conditions and causes of hyponatremia, but none of them are germane to hiking expeditions. It can be caused by drinking too much water, but only in long term strenuous exertion like you would expect from a marathon or triathlon. If you’ve been running on a trail for hours and hours or over the course of several days and have been gorging yourself on water, then it is possible you could have caused a bigger problem with your sodium level.

But it takes a whole lot of drinking water to cause this problem and it’s honestly doubtful that the majority of people could exert themselves enough to cause it without passing out or giving up first. 


Electrolyte imbalances

The human body’s muscle functions and nerve reactions depend on the proper exchange of electrolyte ions inside and outside of cells in order to work the way they should. There are many electrolytes in the human body that separate into positive and negative ions when they dissolve in water. Here are a few of the most common electrolytes in the human body and their normal concentrations:



4.5-5.5 mEq/L


97-107 mEq/L


3.5-5.3 mEq/L


1.5-2.5 mEq/L


136-145 mEq/L


The majority of electrolyte imbalances are caused by such various instigators as loss of bodily fluids from prolonged vomiting, diarrhea, sweating, or high fever; inadequate diet; hormonal or endocrine disorders; kidney disease; and complications from chemotherapy. As you can tell, none of these are related to hikers’ activity on a hiking trail. The amount of sweating required to cause an electrolyte imbalance is very high, but if you are worried about it, then consider consuming a specially designed sports drink on the hiking trail in addition to normal amounts of water. 


Man with a hiking backpack overlooking the mountains.

The shoulder straps on a rucksack might inhibit blood flow and cause hiker’s hand swelling.


Water retention

Water retention has everything to do with how much water you drink and how high your sodium level is. If you were dehydrated at any point, either before or during your hike, then you could see some water retention at some point. Any hiker who might be on their period should know that water retention is very common during that time, so don’t be surprised if some water retention occurs.

It’s something that happens in the circulatory system for a variety of reasons ranging from harmless to serious. It could be kidney failure, but there are other very visible symptoms of kidney failure. If all you’re experiencing is painless hand swelling, then it’s quite unlikely to be a serious medical condition like kidney failure. 


High blood pressure

Last of the common prescribed causes of hand swelling on the hiking trail is high blood pressure. This is the least likely culprit for at least two reasons. For one thing, if you take a look at what some of the common causes are, it’s unlikely for frequent hikers to have many of the attributed on the list. If they do, no judgement, but it’s also rare not to know it.

In any case, high blood pressure comes from long-term lifestyle or genetic factors such as drinking more than 1 or 2 alcoholic drinks per day, smoking, being overweight, lack of physical exercise, stress, old age, family history, sleep apnea, chronic kidney disease, or adrenal and thyroid disorders. 

The other reason high blood pressure is an unlikely cause for hikers who have no history or diagnosis of high blood pressure already is that hiking causes the heart rate to increase. More blood is required, so blood vessels expand. This expansion, called vasodilation, causes blood pressure to decrease. 


The circulatory system and hand swelling

Now that we’ve taken a look at some of the things that so-called expert-answers typically attribute swollen hands to, let’s talk about what is actually happening in your body that’s causing swollen hands on the hiking trail. Blood flow is controlled by the heart, which works as an engine, pumping blood around to the different parts of the body and receiving back what isn’t absorbed by body tissue. This is what happens in the arms, for example.

One theory holds that adding pressure on the shoulders can prevent fully open blood flow of unabsorbed blood back to the heart, causing that unabsorbed blood to pool in the hands somewhat and causing hand swelling. This is a partial cause of hand swelling, but anecdotal evidence from hikers who have experienced hand swelling without even wearing a rucksack and the clear prevention of hand swelling that the use of trekking poles affords indicates that shoulder straps are not the sole cause of hand swelling.


Trekking poles to prevent hand swelling

Continuing with our brief circulatory system explainer, we’ll point out now that the heart does send blood out into the body but it isn’t the only muscle powering blood flow. Muscles wrapped around veins contract when the human body moves. When these muscles contract, blood flow is propelled forward. When the muscle is no longer contracted, the blood cannot flow backward. As you can tell by its name, the circulatory system is a circuit, which means that this contraction and release of muscles for movement propel blood round the whole body until it gets back to the heart.

This is one explanation for why we don’t see feet swelling as often as we see hand swelling on the hiking trail. Our legs are constantly moving when we hike, which means those muscles are constantly contracting and releasing, which means blood can’t build up in the legs that way it does in the arms while we hike. The use of trekking poles can cause the muscles in our arms to contract and release, preventing hand swelling incredibly efficiently. 


A man with trekking poles in the snowy mountains daytime.

Trekking poles can greatly reduce the chances that your hands swell on a long hike.


Blood flow and hand swelling

OK, so now we have a much clearer idea of why our hands sometimes swell when we hike. What should be clear from the information we’ve provided so far is that swollen hands are very common amongst hikers and easily reversible. If we could give a short answer as to the cause of hand swelling on the hiking trail, we’d have to say it’s all about the blood flow. If you notice swelling while you’re hiking, just know that it’s most likely nothing more than a side effect of aerobic exercise you’re engaged in or from pressure or lack of activity in your arm muscles.

There are a variety of quick tips and tricks you can try on the hiking trail to prevent and get rid of swollen hands and fat fingers, but the best bet is going to be using trekking poles. It’s the best way to keep your arm muscles involved in aerobic activity that will cause the muscles to contract and keep blood flow pumping so there is not a build-up of blood in the arm that will case hand swelling.


How to prevent hand swelling while hiking

If you don’t have any trekking poles for whatever reason, there are two things that you can do without the aid of any other tool while you hike. You may look a bit crazy, but hikers who have been hitting the trails for long enough will know exactly what you’re doing. One thing you can do is regularly hook each of your thumbs underneath your rucksack shoulder straps and lift them up off your shoulders, which will relieve pressure as well as engage your arm muscles.

You can also make arm circles, swinging first one arm and then the other like a windmill on either side of your body. This should exercise your arm muscles and shift the shoulder straps of your rucksack enough to provide increased blood flow. Neither of these exercises will give you the benefits of trekking poles, but they should provide some relief in a pinch. 


Two people hiking with a brown dog in the mountains with a blue sky.

Blood flow back to the heart is aided by the contraction of muscles near a vein.


Final Verdict:

It can be scary to look at your hands in the middle of a trek and see fat fingers and swollen hands. If you haven’t had the chance to read about this common problem, it can seem like a serious affliction belying an even more serious chronic affliction. There are many webpages and well-meaning posters on hiking forums giving what appear to be expert-answers, but there is a ton of incorrect information on the internet about hand swelling on the hiking trail. There are many serious conditions that often erroneously enter the conversation such as heart disease or an electrolyte imbalance, but neither one of these is likely to manifest in hand swelling only without any pain or other serious side effects. 

The human body is very good at regulating itself in terms of electrolytes and the other various things it needs to keep moving. Hand swelling is more indicative of the constant battle between gravity and the circulatory system. It takes a lot of effort to keep up the blood flow required to keep us alive and kicking. The body has some tricks to keep the blood flow where it needs to be, one of which is the contraction of muscles near blood vessels to keep the blood moving.

When we hike, we aren’t always using our arm muscles for anything. This can create a kind of backup in the circulatory system that is neither serious nor life-threatening, but will manifest itself in swollen hands. The best way to prevent swollen hands while hiking is to use trekking poles. It’s also wise to remove or loosen rings and watches before you hike to prevent them getting stuck if your hands do swell. 


Bonus tip: Listen to Professor Dave explain more about blood vessels in this educational video!


Related Articles

Leave a Reply

Your email address will not be published.

Back to top button