Foot Blister Prevention & Treatment

Foot Blister Prevention & Treatment

Prevention. How many times a month do you hear or see “prevention” used in commercials, articles and blogs?

Perhaps the word is over-used in our society, but in regards to hiking, prevention of blisters will save you miles of pain and suffering. Who wants their trip to turn into a suffer-fest for days on end?

Keeping your feet dry, cool, and friction-free will usually prevent blisters. This article will show you how to accomplish that and how to  treat foot blisters if you get one. A list of what you will need and where to get it follows.

You want to ensure you have a fitness and conditioning plan (with Fit for Trips ) that includes extended walks/hikes to get your body in shape and to adapt to the rigors of long hikes. This fitness plan should include getting your feet in shape. The military did some testing and found that soldiers who wore their boots for 20 hours over a two week period prior to maneuvers had far fewer blisters than those who did not. It takes time to condition your feet so put that into your trail fitness plan.

What Your Feet Wear

Properly fitting boots/hiking shoes can go a long way toward preventing most blisters but don’t be fooled into thinking you can’t get a blister because your shoes feel perfect. A true story from a trip I led: My friend had heard about a famous master bootmaker in New Hampshire. We went to the bootmaker and had his feet measured and molded by the master bootmaker. A few months later my friend received his custom-made heavy leather boots. The boots were fitted for the slight differences of each foot (which we all have). He worked in the yard and went on a few neighborhood walks. He never wore them more than a couple of hours at a time, yet declared they were perfect. Very well. We hit the trailhead lugging our 50 pound packs (this was back in the day). The first mile was a steep uphill grade. The constant heel rub that resulted from the stiff boots gave my friend a blister within the first mile of a week long backpacking trip in the Rockies.  Needless to say he was miserable all week and did no side hikes to waterfalls, peaks, or grand vistas. I wish I had known then what I know now about blister prevention and treatment (but then I wasn’t the one suffering).

These days not all boots/trail shoes need breaking-in time as stiff leather boots do, yet taking time to wear them in advance of your trip to check for any irritations or hot spots is part of necessary preparation. Taking the time to do so will pay off.

We won’t discuss choosing specific footwear here but will give you a few pointers (we’re talking hiking footwear here, not specialized mountain climbing or expedition boots, though the same principles apply). Buy your hiking footwear from a knowledgeable outdoor store and have them help you pick the right boot/shoe for your intended use and fit you properly, allowing for such things as foot swell after hours of hiking. You will probably have to try several different pair in order to find the proper fit so allow adequate  time for the task. The store should have a slant-board so you can test for downhill toe room and heel slippage. Also, it is best to visit the store later in the  afternoon when your feet have swollen to near their maximum size (yes, feet change sizes when in use, particularly while hiking). A knowledgeable salesperson should also show you different lacing techniques to help get a better fit. If you have arch issues a different insole may help attain a better fit (performance insoles such as Super Feet, Sole, and Soft Sole are all good; see links below). It is wise to take the hiking socks you prefer to use when trying on new footwear. Socks can be used to “fine tune” the fit if done properly.

Before you purchase footwear, find out the store’s return policy. Take the new boots/trail shoes home and wear them around your house actively for a while to make sure they are comfortable.  This way you can still exchange them for a different pair if needed (i.e., don’t wear them outdoors just yet). Once you’re satisfied with the fit, start taking long neighborhood walks and then actual hikes. Some problems may not show up until your feet are hot, sweaty, and tired!

In this era of lightweight gear, many long distance hikers prefer trail shoes over boots (AT, Camino del Santiago, etc.) with no break-in required. Full leather boots typically need a  “break-in” period. This is truer for all-leather boots such as the classic full leather Asolo TPS backpacking boot.  Essentially, this means you should gradually begin to use your new boots well before your trip. Heat, sweat, and movement will get the boot and your foot used to each other and give you a chance to check for “hot spot” foot irritation.  In other words, don’t start a trip with brand new boots.  Small areas can sometimes be stretched out a bit by a good cobbler to allow for bunions, calcium deposits, and other unique fit issues. Break-in is less important for many of the leather/synthetic blends that are on the market today, such as the Asolo Fugitive, the La Sportiva Trango, or the Vasque Breeze.  However, it’s a good idea to get used to your new hiking footwear incrementally.  

The last word on footwear is to ignore price over fit. If your boots don’t fit or support your foot properly when on the trail, you’d gladly pay the 25-50 dollars you saved to make your foot pain go away. Price doesn’t necessarily equate to a good fit. Go for the good fit regardless of the price.

Why Blisters?

Blisters on the feet are caused by heat from friction, humidity (the foot has 125,000 sweat glands), and your skin layers moving independently of each other instead of moving together as a unit.

Try this:  put your hands together and rub them against each other hard and vigorously for ten seconds.  Did you feel the heat building up from the friction?  This is the same process that creates blisters.  Friction heat causes an abrasion of the epidermal layers, releasing fluid under the skin in the form of a blister.  In some ways you can think of it as a burn.  This feeling of heat and friction that precedes an actual blister is called a “hot spot.”  This is the perfect time — before getting the blister — to take action to prevent blister formation, and ultimately much pain.  The two things you can do are:  

1. Reduce the amount of friction being applied to the area.

  1. Protect the affected area from further damage.

The next step after proper footwear fitting is choosing the proper combination of socks to reduce friction and manage moisture in order to reduce the possibility of a hot spot developing.

A quick note on foot moisture. A thick sock stuffed inside a leather or waterproof boot while hiking all day is certain to keep your feet damp and blister prone. Let your feet air out during breaks by taking off your boots/shoes. If your socks feel really damp change into a dry pair and strap the damp ones on your pack to dry. Clean your feet with alcohol or wipes at the end of the day or soak your feet in a cool stream. One other trick — have a completely separate pair of clean, dry socks for sleeping only. Keeping your feet clean and dry will go a long way toward preventing blisters.

For those with really sweaty feet, there are antiperspirants for your specific needs (see links below), and yes, they actually work. Antiperspirants for feet are most effective if they are applied to clean feet just before bedtime and worn with a clean, dry pair of thin socks (your designated sleeping socks). The antiperspirant will soak into your skin overnight and result in less foot moisture the next day.

Foot powders are nice to use before bed, but the military did some testing on these products. Soldiers who used foot powders before maneuvers actually got more blisters than those who didn’t use powder. The powder acts as micro-grit once it becomes moist and rubs the foot with a sandpaper-like effect, so keep your foot powder for end of day use when your feet are dry.

Sock Harmony

Please note we only recommend the best proven sock materials for hiking: merino wool and Coolmax (polyethylene) due to their moisture handling properties and quick drying time. Why no mention of cotton or cotton/nylon blend socks? Quite simply, such sock materials do not handle moisture well — once wet they stay wet for a long time. Moisture is a major factor in causing blisters along with cold feet. Cotton is great for casual wear but not for active outdoor pursuits. Nylon fleece socks are nice around camp but not for hiking.

Modern merino wool socks are very soft and do not itch for 99.5% of the population (unlike the rag wool socks of old). They can be machine washed and dried with your typical laundry load — no special care needed other than washing in cold water (hot water will cause wool to shrink). One great thing about wool is it can handle a lot of moisture before it feels damp. It doesn’t dry as fast as Coolmax but dries much faster than cotton. Even a moderately damp merino wool sock will feel dry on your foot.

The foot and shoe need to be in harmony or the chance of getting a blister will increase dramatically. The more flexible the sole, such as a trail hiking shoe or lightweight fabric boot may have, the less need for a liner sock because the sole of the shoe can bend freely with your foot thus reducing the friction (assuming you have a good fit). This is why many hikers are fine wearing just a pair of merino wool or Coolmax running/hiking socks (you may also consider the Wright Socks double layer sock used by many ultra-distance runners).

Stiffer soled boots, which don’t move as easily with your foot, are often best worn with a very thin liner sock next to your skin and a thicker wool hiking sock next to the boot. The liner sock should fit like a second skin (no fabric bunching, no obvious toe seam), which reduces friction with the outer sock and helps move moisture away from the skin to the outer sock thus reducing the opportunity for a hot spot to develop on your foot. Moisture control is a key component in avoiding blisters — plan in advance to keep a change of dry socks on your feet throughout the hiking day unless you know for sure your feet are not blister prone.

A typical liner sock is a very thin piece usually made from polypropylene (Coolmax) or merino wool blend.  Liner socks provide an extra layer of protection for the bare skin of the foot and prevent hot spots from forming.  Thin liner socks dry out quickly, allowing you to change into a dry pair of socks every few hours. Let your bare foot air out a few minutes before replacing your socks (even in cold, just throw a jacket over your bare feet for a moment or two — weather conditions allowing). Some people love liners, others hate them. Again, proper fit is key; the liner should be your layer of “second skin.”  Either way, if you are prone to blisters get a pair to experiment with.

The next piece of blister prevention is choosing the right hiking socks to wear. Again, fit is a key factor. The sock should fit your foot snuggly (it should have a bit of spandex in the wool blend). You should not be able to feel a toe seam. Sock thickness will affect the way your boots fit. You may want to start with a medium or thin cushion, particularly if you are using a liner sock. Merino wool socks (blended with a bit of nylon for durability and spandex for stretch) have become the preferred hiking sock material over the past 25+ years both for comfort and moisture management. Of course socks, like other things, are a personal preference item. Your mileage may vary (YMMV).

Smartwool merino wool hiking socks rocked the hiking world in the 1990s and are still the standard. Now, many companies make merino wool hiking socks of various quality. Darn Tough makes excellent socks that last longer and feel better than any other brand I’ve ever owned, and they are made in the USA. They are not cheap, but they are guaranteed for life (see Sock links below).

Always try some different sock combinations on shorter hikes. I prefer to use a slightly thinner sock as it dries quickly, takes up little space in the pack, and weighs next to nothing. Always carry at least one extra pair of dry socks just in case your feet are super-sweaty, a torrential downpour pops up, or you slip on a rock while crossing a creek.

Blister Treatment Kit

Every spring I run into Appalachian Trail thru-hikers who are hiking in their camp shoes — usually Chaco sandals, Crocs, or similar (see links below). Invariably, they could no longer hike wearing their boots or trail shoes due to blisters. Their goal then becomes hobbling along to the next “zero day” in town so they can stop hiking long enough to treat foot blisters. It’s amazing how many AT hikers don’t have a clue how to prevent blisters much less how to treat one. That’s just crazy!

Carrying a few small items to treat hot spots on your feet and toes, as well as a little knowledge, can keep your hike comfortable and prevent the formation of painful blisters that can ruin your trip. When you properly take care of it, a blister can start to recover in six hours and is no longer painful after about 48 hours. Improper care can result in not only a lot of walking pain but can potentially become an infected mess filled with bacteria.

The items listed below are available in drugstores and grocery stores as well as the usual big-box stores and online.

All of these items should be in every hiker’s First Aid kit:

  • A package of moleskin, which comes in thin and thick versions.  It’s good to have both if you are prone to getting blisters and/or to treat fellow hikers. Thin will do most of the time.
  • Tincture of Benzoin (a type of tree sap) comes in a small tube or ampule. It’s tacky properties help moleskin or tape stick to damp, sweaty feet.
  • Waterproof first aid tape, athletic tape (Leukotape) or duct tape. Can be used prior to the hike to cover an area prone to blisters or to hold moleskin in place.
  • Alcohol wipes or gel to clean the affected area and dry the skin.
  • Antibiotic ointment (triple antibiotic preferred).
  • Small first aid scissors/trauma shears for cutting tape on skin.
  • Sewing needle or small safety pin.

Blister-Prone? Prevent it!

For those prone to blisters (narrow heels slipping in boots or toe rub), placing tape to cover the affected area can be quite beneficial. For heels, use a piece of one inch or wider tape about ten inches long. Apply on clean, dry feet — place the center of the length of tape over the point that is blister prone. Lay the tape down smoothly on the skin, taking care to not get any folds. Wrap the two ends across each other so tape is sticking to tape. Cut off the excess. The key is getting a good, clean surface to stick to and using a good quality tape. Use the same method for areas on the ball of the foot. Leukotape sports tape (see links below) has become a long distance hiker favorite for blister prevention.

If your sweaty feet won’t hold the tape well and rolls up after a while, try using Tincture of Benzoin prior to taping. It will form a tacky surface on your skin which will hold the tape in place. Spread the tincture over the area to be taped. Let it air dry for 3-4 minutes, then lay down the tape. Take care to lay the tape smoothly without creating wrinkles.

If you have toes prone to blisters, you can do something similar. For toes, use narrow tape (one half inch). Wrap the toe with three turns, each turn lying about halfway over the prior one. Start and finish the wrap on top of the toe. If you’re prone to friction blisters between toes, use a skin anti-friction lubricant gel such as offered by BodyGlide, Monistat or Lanacane (see links below). A lubricant can be used on other places on your body that get friction rash, too, such as when you are wearing sweaty clothes for hours on end.

Another method for treating toes: start with clean feet — wipe with alcohol to remove dirt, moisture, and skin oils. Coat your blister prone areas with tincture of benzoin. Let it air dry for 3-4 minutes — it will be sticky. Now apply a lubricant over the tincture of benzoin. Vaseline will work, but the formulated types such as Body Glide, Sport Stick, and similar will work longer. The lube will need another application after 4-5 hours of walking.

How to treat foot blisters

Hot Spot & Small Blister Treatment  

While doing your training hikes, take time to pay attention to how your feet feel. Boot/shoe laces that are too tight or too loose can be the cause of hotspots on your feet. Your feet do swell as you hike, and your boot laces may need adjusting to accommodate the situation.

When you do notice a hot spot, don’t hike for another hour thinking it will go away. Stop and take care of  it. If the laces just need some adjustment, great, but if a lacing change doesn’t help, take time to stop, sit down, and pull off that sock. Yes, your buddies may give you a hard time for stopping, but it’s your foot feeling the pain, not theirs.

Some people treat a hot spot by using the same taping preventative as given above. However, part of the problem causing the hotspot is moisture. Once you start hiking, moisture is going to form under the tape. Due to the removal of friction by the tape, the hotspot may not increase in intensity, but you’ll still feel it. Therefore, I prefer to treat a hot spot with the same method as a newly formed, small blister. Larger blisters may require slightly different treatment.

Locate the hot spot (or small, newly formed blister) on your foot. Clean the area to be treated with alcohol wipes or gel, which will remove the moisture and body oils, allowing the adhesive to stick much better. If you have have tincture of benzoin, apply it around the hot spot, basically where the moleskin will lie. Grab the sheet of moleskin and apply it this way: cut a square piece of moleskin about one-half inch larger than the hot spot. Fold the moleskin piece in half. Now cut a hole into the middle of the folded sheet. Make the hole just big enough to surround the hot spot without touching it.. You want the hot spot to remain in a pressure-free “donut hole”. Next, trim the outside corners of the moleskin square so it now has eight sides — it’s the points of the corners that tend to pull up first (especially if tincture of benzoin wasn’t used). If the moleskin square is larger such as two inches square, you may want to trim the points twice to make it more of a circle without corner points.

In some situations, you may need to use a piece of tape to hold the moleskin in place. Just cut a little hole in the tape above the “donut hole” in the moleskin. Allowing the skin to breathe will quicken the healing process. Often the hotspot will be gone when you wake up the next day; a little blister will still be tender, so you may to want to cover the spot with moleskin and tape to prevent further issues. For a little blister you’ll definitely want to use moleskin for a few days.

You may come across recommendations for “gel” patches for use on hot spots and small blisters. I do have some in my kit to try at some point, but so far I’ve not had any hot spots on which to experiment.

As a side note: Super Glue on top of a hot spot works pretty well (don’t use it on a blister, though), but not many hikers carry a tube of Super Glue in their kits.

Big Blisters

If you feel a hotspot, ignore it, and keep walking, you may soon be in a lot of pain because you now have a big blister. More than likely it will be your hiking buddy that has the blister because you read this article and know how to prevent blisters as a wise hiker should.

If the blister is the size of a nickel and filled with fluid, you may be tempted to pop it, but you don’t want to do that.  Try to handle the blister without popping it for a few days (there are exceptions addressed below). If it is properly treated, the body will absorb the fluid and start growing new skin under the hermetically sealed protection of the blistered skin. Opening a blister offers a warm, moist path that bacteria just love (foot odor comes from the bacteria on your feet). We will address an open blister in a moment — just know that opinions on this differ widely and recommendations seem to change as often as Daylight Savings Time.

The treatment begins the same as for the small blister — clean the area and spread some tincture of benzoin on the skin around the blister.

Next put some antibiotic ointment on the blister to keep bacteria away (just in case it does pop while you’re walking).

Cut a piece of moleskin as explained above. Since the piece of moleskin will be fairly large, take time to trim all the corners so that it is quite round. Make sure the hole in the middle doesn’t touch the blister. Consider how the moleskin will be compressed with boot on — you don’t want anything to touch the blister. If in doubt, add a second layer of moleskin to ensure protection of the blister.

Tape in place so the moleskin won’t move while you are walking. Cut tape strips long enough to reach around your foot in order to hold the moleskin firmly. Then tape across with a second piece of tape at a right angle to hold the ends of the first tape layer in place.  

Popping Blisters

There are good reasons to pop a blister. A blister in a stressed area of the foot (the heel or ball of the foot being common ones) is a good reason for popping it as part of the treatment. Even if a blister popped while in the boot, the treatment is almost the same. Leave the skin in place whether it’s already popped or not.

Your First Aid kit should have a few safety pins and ideally, a sewing needle. Sterilize the needle (or safety pin sharp point) with soap, alcohol, or heat until it glows red. Pierce the blister at its lowest side close to the foot to enable the fluid to drain. Massage the blister with gentle pressure to push the fluid out. Once the fluid has drained, dry and clean the area of the blister again. Apply antibiotic ointment on the blister and around the drain hole to prevent the entry of bacteria into the blister.

Now apply tincture of benzoin to the surrounding area where the moleskin will be placed. Apply two pieces of shaped moleskin, one on top of the other. The blister spot is going to be very tender and sore so make sure it’s protected.

Tape the moleskin in place so it won’t move while you are walking. Cut tape strips long enough to reach around your foot in order to hold the moleskin firmly. Then tape across with a second piece of tape at a right angle to hold the ends of the first tape layer in place.  

Replace the blister covering the next day, before the tape or moleskin start to lift and cause additional problems.

Final Words

Preparation and Prevention are the keys to avoiding blisters specifically as well as many other aspects of your trip. Those who do not hike regularly may have never experienced a debilitating blister on the trail. It is a painful lesson to learn. Be prepared and you’ll come out miles ahead!

Item Links

The following list is comprised of items that have been proven to work and are ranked highly by experienced wilderness medicine experts. You’ll notice some popular items, such as Spenco Second Skin not listed. Such items are often good for other uses, just not for foot blisters in particular, despite what advertisements may say.

Performance Insoles

Performance Insoles

Foot Antiperspirant
Certain Dri Antiperspirant Roll On 1.2oz

Carpe Antiperspirant Foot Lotion (Prevent Sweaty Feet, Block Sole Sweat)

DrySol and at many drug stores

Liner Socks
Liner socks – merino wool, polyprolylene

Hiking Socks – merino wool

Smartwool Socks
Darn Tough Socks
REI Merino Wool Socks

Blister Kit Items

 

  • Alcohol Wipes – prep pads
    Drug stores
    Amazon
  • Antibiotic Ointment
    Drug stores and big-box stores
    REI
    Amazon
  • Skin Lubricant

BodyGlide Liquified Powder
Lanacane Anti-friction Gel
Monistat Chafing Relief Powder Gel

Post Hike / Camp Footware

Chaco sandals
Teva sandals

Crocs clogs

by Eponymous Hiker

2 Comments

  • Avatar

    Brenda Reply

    Thank you so much for this comprensive report on blisters. I am new to hiking and know absolutely nothing about blisters; prevention or treatment. I was confident that a good boot was the solution. My midrise Merrill’s are awesome but my narrow heel caught up with me after a 10 mile hike. I returned to my 5 mile hikes but found that bandaids did not protect the blisters and after three days and a much larger blister decided to let it heal and research the subject. Armed with this information I am ready to get my new supplies and hit the trails again. Sure appreciate it.

    • Avatar

      Amanda McCadams Reply

      Hey Brenda, So glad that you found this information useful. Hopefully you’ll have much happier hikes from now on out.

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