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The Most Awesome Explanation for Swollen Hands When Hiking!

Let’s get this out in the open. I don’t have the most slender fingers to start with. So, with that said, when I hike my fingers get very swollen. I have found that during hot and humid and long summer day hikes my fingers turn into Vienna Sausages.

Because I have a curious mind, and want to correct this phenomenon, I decided to look into why hands swell when we hike.

The main reason that hands swell when hiking is due to increased centrifugal force. Centrifugal force increases when you swing your arms during hiking. After hiking a number of miles your hands start to swell.

Other Theories

Other theories include impaired blood flow or congested lymph drainage from tight backpack straps, and impaired electrolyte imbalance. We recommend several backpacks with appropriate straps to prevent blood vessel or nerve compression.

Let’s take a closer look at these theories to see which ones hold water. Pun intended.

I promise not to bore you, but let’s start with how your body works.

Theory #1: Impaired Blood Flow or Congested Lymph Drainage Due To Tight Backpack Straps

Oftentimes new backpackers use a backpack incorrectly. They tighten the shoulder and chest straps thereby carrying too much weight on their shoulders. But does this cause the hands to swell? Let’s start with a brief anatomy and physiology lesson.

The Anatomy and Physiology Of The Upper Arms and Shoulders

I will try not to bore you…zzzz! Let’s all agree that swelling is when fluid enters your fingers and stays there leaving us with puffy fingers.

Because blood vessels, including the arteries and veins, carry blood to the arms let’s start there. Also, the nerves to the arm and hand travel through what is called the Brachial Plexus (a group of nerves) and down to the hand and fingers.

The Blood Vessels

Blood vessels are part of the circulatory system that begins with the heart. Our heart pumps blood out into the arms by the way of arteries. Once at the destination, the fingers in our case, the oxygen from the blood is given to the cells and then the deoxygenated blood returns to the heart for a new shipment of oxygen. It is transported back to the heart by way of the veins.

When this transport system gets hung up then swelling may occur. Say, for example, you are hiking and you tighten your straps down too much on your shoulders. This impedes the blood from either getting to your fingers or returning to the heart.

Blood Vessel Compression

But does compression on the blood vessels cause your fingers to swell? Not likely.

When you compress the arteries AND the veins blood flow, on the whole, is restricted. It is as if you have put a tourniquet on and prevented fluid from passing.

What happens when using a tourniquet? First, the area will experience ischemia or lack of blood flow. The hands and fingers may blanch (turn white) or become light blue. Meaning they are not getting enough oxygen.

Also, they may feel tight but not necessarily swollen. The longer the compression, the more painful this becomes.

hiker wearing backpack on shoulders
hiker wearing backpack on shoulders

The Nerves

The nerves from the shoulder area become compressed. This leads to tingling and eventual numbness to the hands and fingers. Like when your foot falls asleep after sitting on it for too long.

This does not lead to swelling just an uncomfortable feeling in your hands.

The Lymphatic System

The lymphatic system works a little differently. The lymph system contains a couple of organs (spleen and thymus) and a network of lymph glands and lymph nodes placed strategically throughout the body.

The purpose of the lymphatic system is to rid the body of toxins, waste, and other unwanted materials. When there is blockage of the lymphatic system a couple of things happen. A blockage prevents fluids from draining (removing the toxins) and the buildup of swelling leads to what is known as lymphedema.

Lymphedema is often found in people who have had radiation from breast cancer or certain surgeries in the upper arm. It is due to damage of the lymph nodes and lymph glands in the upper arm. If this is you, then you may already experience lymphedema that worsens when out hiking.

While symptoms can worsen from hiking, most people that experience hand swelling have not had surgeries due to cancer or after shoulder surgery.


Nope, this is not the case for the mass majority of people who suffer from hand swelling when out hiking. If you have compromised circulation or lymphatic system, yes, but we are looking at swelling in people without pre-existing conditions.

Theory #2: Hyponatremia and Electrolyte Imbalance

One would think that dehydration causes your hands to swell. But some theorize that it is quite the opposite. A couple of things happen when we hydrate with only water during hiking. First, we prevent or delay dehydration. Which is a good thing. Second, we upset the electrolyte balance, primarily sodium. Which can be dangerous or even fatal.

Let me explain. To remain in balance (hydration-wise), we need to balance both water and electrolytes. This is what Gatorade has tried to do for years (I will rant on Gatorade in a minute).

However, when you drink water only, then you don’t get the required sodium to keep the system in balance. Excess water to electrolytes is known as Hyponatremia, which means not enough sodium in the fluid.

When we experience hand swelling from hiking is this due to hyponatremia? Most likely, NO.

Symptoms of hyponatremia from the experts

According to the Mayo Clinic (wicked smaht scientists and doctors), hyponatremia symptoms include the following: headache, nausea, vomiting, loss of energy, restlessness, muscle spasms/ weakness/ and cramps, seizures, and coma. They do not mention swelling of any kind.


While hyponatremia is a serious condition, it is highly unlikely that your hand swelling is due to hyponatremia or low sodium to water ratio.

[Fun fact: sodium in Latin is natrium. Hence Natrium or Na on the periodic table.]

Back to Gatorade for a moment: This is the way I heard it.

I once heard that when Gatorade came on the scene in the 1960s it was used to prevent dehydration and hyponatremia. Ok. But unfortunately, the required concentration of sodium or salt in the beverage did not make for a great tasting beverage.

When Gatorade hit the consumer market, people didn’t like the taste. So, Gatorade added more sugar and reduced sodium levels. This was to make it more palatable.

But in doing so, Gatorade diluted the drink’s power to prevent hyponatremia.

What they did do was create the Sports Drink industry. And the rest is history.

Early Gatorade Commercial

Theory #3: Centrifugal Force From Swinging Your Arms When Hiking or Walking

When we walk, hike, and run we rely on swinging our arms to keep in balance and maintain forward motion. Swinging the arms has a potentially detrimental effect on fluid dynamics in the arms.

A swinging motion, which is a portion or arc of a full circle of motion, increases the centripetal force up toward the shoulder. Also, the normal force causes fluids to push outward toward the fingers; This outward force is called centrifugal force.

More about centrifugal force and why it is the number one culprit in hand swelling. To understand what is happening in the body, specifically the fluid we should look at the old contraption from science class: The Centrifuge.

laboratory centrifuge represents swinging arms and hand swelling
laboratory centrifuge

What does a centrifuge do?

A centrifuge is a device that is used to apply centrifugal force to liquids of different densities. In a lab, the denser liquids will be pushed away from the opening of the test tube and the less dense liquids stay closer to the opening.

When we walk and swing our arms we act like a centrifuge. Albeit much more slowly giving us the understanding that this is a slow process. Meaning, your fingers don’t swell immediately on your hike but maybe after 3 to 5 miles.

Fluids from inside of our cells get ‘pushed’ out and remain in our fingers. This happens outside of what is happening in the circulatory system (arteries and veins). Meaning, the blood continues to flow and provides for oxygen to reach the cells while carbon dioxide is removed from the cells as the blood heads back to the heart.

Arm Swinging Motion and Centrifugal Force

Let’s take a look at centrifugal force when applied to an arc of motion as in walking. Watch the beginning of the video as the person is rocking the cup back and forth to get it started. This is similar to what happens when we walk with our arms swinging.

Centrifugal Force


Ding, ding, ding! For these reasons we believe that Centrifugal Force is the number one reason why hands swell when hiking.

What Are Some Other Factors That Play A Role In Hand Swelling? And Why?


According to Altitude Medicine exposure to high altitude can cause swelling to occur in the arms, face, and legs. This is caused by pulmonary edema and often occurs without any other symptoms.

Pulmonary edema is when the lungs are unable to handle the different pressures outside verse inside the lungs. Water begins to pool inside the lungs, and it becomes challenging to breathe. This is a very dangerous condition.

mountain climber at altitude pulmonary edema
mountain climber at altitude


Yes, pulmonary edema can cause hands to swell but this is a different situation than we are describing with “everyday” hand swelling. Like when you are on a jaunt around the park or the local trails.

Also, if you experience symptoms of pulmonary edema seek medical attention, immediately.


Humid days, especially in the summer, cause increased hand swelling. A hot day will cause the hands to increase circulation and begin to heat up. Normally, when this happens our hands sweat, and the sweat is evaporated.

This is called evaporative cooling and is how we decrease our body temperature. Unfortunately, during humid days, our body is less able to evaporate the heat from our skin and causes a backup of fluid. Fluid from beneath the skin is unable to escape and causes the hands and fingers to swell.


Yes, hands can swell with humidity. As a matter of fact, couple a hot and humid day with swinging your arms on a hike and you have increased hand swelling.

Cardiovascular Activity

According to the Mayo Clinic, exercising causes hands to heat up by the opening up of blood vessels. This leads to increased blood volume and therefore a chance of increased swelling.

I tend to think that cardiovascular activity such as stair climbing, walking on an incline, or running might lead to swelling for other reasons. Like the act of arm swinging as noted above.

Either way, the increased activity, heat and arm swinging can complicate the issue.

Salty Foods

It is well known that eating salty foods may cause your hands to swell. I have also noticed that my legs feel ‘anxious’ after eating a meal that is high in salt. Especially after a long hike where my salt level may be depleted.

After eating a salty meal, our cells attract water into them to balance the salt to water ratio. Some medications for treating arthritis causes water to be held in the cells and become swollen.

Cold Weather

Cold weather does the opposite. Blood vessels constrict causing the hands to lose fluid from them during cold days.

However, quickly warming the hands may cause the hands to bring in excess fluid (warmblood) and cause the hands to swell. This condition is very painful. That is one of the reasons why healthcare workers advise you to warm tissue slowly.

How Do I Prevent Or Stop My Hands From Swelling During A Hike?

For the remainder of the article, we are going on the premise that hand swelling is primarily caused by the centrifugal motion of arm swinging.

I believe this theory for the following reason. After a day of hiking with swollen fingers, I sit in the car and my hands miraculously return to normal. Meaning, I don’t have to do anything and the swelling disappears.

Why do I think this happens? First, I have stopped swinging my hands and reduced the centrifugal force applied to them. Second, I have allowed the cells to remove the swelling and the circulation to head it back to the heart to be disposed of.

trekking poles to prevent hand swelling
trekking poles

When You Are On The Trail

  1. Raise your hands above your head and pump your hands into fists: This will allow gravity to assist in reducing the swelling in your hands. This act also allows your muscles to help squeeze out the swelling. It may take some time but you should notice a big difference in about five minutes. Just be careful not to stumble when hiking
  2. Bend your elbows so that your hand is higher than your elbows: Like number 1, this allows our bodies to reduce swelling.
  3. Try hiking poles: Hiking poles do a couple of things. They cause your hands to use muscles which act as pumps to pump out fluid. And they cause you to bend your elbows and keep hands near or above your elbows.
  4. Stop hiking for 10 minutes: When you stop hiking you stop swinging your arms. Therefore, the swelling can be absorbed back into your bloodstream, and off it goes.

The main idea is to do 3 things: elevate your hands, contract the muscles in your hands, and stop swinging your arms.

Related Questions

Hiking with Raynaud’s Disease

If hiking weren’t hard enough people with Raynaud’s Disease or Phenomenon have to take more caution when they hike.

According to Medline Plus, Raynaud’s is a rare blood vessel disorder primarily affecting the fingers and the toes. “It causes the blood vessels to narrow when you are cold or feeling stressed. When this happens, blood can’t get to the surface of the skin and the affected areas turn white and blue”.

5 Tips for hiking with Raynaud’s Disease

So, how can one hike with Raynaud’s? A few things help to alleviate or reduce the symptoms of Raynaud’s.

First, keep your hands warm with gloves while hiking in cooler weather. This sounds like a no brainer. However, because I live in the East I often forget how cold it can get when out hiking in the mountains. Someone with Raynaud’s has to be extra careful.

Second, exercise regularly to improve your circulation. Again, no brainer right? Many times new backpackers just start hiking or going on longer and longer walks. Exercise should be intentional and consistent. Meaning, the more frequently you perform cardiovascular exercise, the more prepared you will be in the mountains.

Third, just chill! Ok, that wasn’t what I meant. People with Raynaud’s often have exacerbations when they are under stress. Practicing yoga or meditation often reduces the chance of reacting.

Last, eat right. What does that even mean? Inflammation can reduce the body’s ability to get circulation to the hands and fingers. Foods such as highly processed carbohydrates cause inflammation. Reducing or eliminating these foods helps to increase circulation in the time of need.

Oh, one more thing. Bring extra clothing. If your gloves get wet, it is a good idea to change them. So, bring extra and your fingers will thank you.

Hiking While Pregnant – Hand Swelling

During pregnancy, the body produces more blood and body fluids to meet the developing baby’s needs. Up to 50% more according to some medical journals.

Because of this increase in fluid, swelling is a normal situation. When a pregnant woman goes hiking, their starting point (in regards to swelling) is already set higher than their pre-pregnancy state. So, for the above reasons, especially swinging arms when hiking, a pregnant woman may experience more hand swelling than normal; and it will occur much earlier than before.

Preeclempsia and a word of caution

A word of caution. Sudden swelling in the hands and feet during a hike or at any other time during pregnancy may be a sign of preeclampsia.

Pre-eclampsia is a complication that may happen after about week 20. It is a serious sign that something is wrong. Symptoms include damage to the organs, high blood pressure, and swelling in the hands and feet.

It is best to seek medical attention immediately.

Hiking With Lymphedema

Another condition where swelling is concerned is Lymphedema. Usually occurring after special types of shoulder surgery or post-mastectomy and radiation.

Lymphedema is damage to the lymph glands, nodes in the upper arm (also leg, but that is not part of our discussion). Hiking with lymphedema can be a challenge. Here are some tips to help manage increased swelling during your backpacking trip.

  1. If necessary, wear a compression garment. This is to keep mild constant pressure on the arm and prevent the arm and hand from swelling.
  2. Use a hiking pole. As we mentioned above, this will keep the hand and arm supported, the elbow bent, and the hand above the elbow. The lessens the chance of increased swelling.
  3. Avoid too much lifting with the affected arm. Most likely, the lymphedema is not in both arms. For that reason, practice lifting your pack with the ‘good arm’.
  4. Elevate your arm. Whenever you take a break get in the habit of elevating your arm. As stated before, this eases up the workload on the arm.
  5. Hike in cooler weather. The increased temperature can get very uncomfortable when wearing a compression sleeve. Also, warmer weather, especially humidity, can cause increased swelling in the hand and arm.

Recapping: Hand Swelling When Hiking

We contend that the main reason that hands swell when hiking is due to the swinging motion and the force at work – centrifugal force. Other factors include humidity, temperature, altitude, pregnancy, salty foods, cardiovascular activity, and lymphedema.

The next time that you are out on a hike and experience swelling in your hands stop and try our advice. We hope that your swelling decreases and hiking becomes more comfortable.

Throughout my research for this article, I relied on several articles by the Mayo Clinic. I recommend the Mayo Clinic for medical searches.