Troubled Soles – Foot Blisters and What to Do About Them

Ed Terry is a guide for Thistle Trekking. He has shared his vast knowledge on blisters and prevention to help our customers on future treks.


A Pair of Walking Boots

What is a Blister?

A foot blister is a pocket of serum that develops over small tears in the layers of skin that cover our feet. Eventually the fluid is reabsorbed by new skin and the blister disappears. Despite being uncomfortable or painful the blister itself is a good thing, protecting against the friction which causes layers of skin to stretch and tear – known as shear.

Blisters can be a serious issue, especially during multi-day trips, and can cause everything from mild discomfort to severe debilitation (and in extreme cases even the need for hospitalisation). They are common enough that the Roman army designed their sandal (the Caligae) to try and avoid them and successive armies have been battling with blisters ever since.

When it comes to walking long distances friction is pretty much inevitable but blisters occur when this friction is increased. The most common causes of this increase are moisture, ill-fitting boots, repetitive motion (e.g. long-distance walking), bio-mechanics (how someone walks) and in some cases simply being more prone to shear.

Although it is often hard to avoid these factors there are several things that can be done before, during and after a long walk to reduce your chances of picking up a blister.

Prevention is Better than Cure

Some of these are standard measures and some may only become obvious after trial and error. However, hopefully the list below will give you some ideas:


  • Proper footwear is essential (although the sheer number of choices can be overwhelming) but more important is ensuring that you ‘break in’ your new footwear prior to undertaking a long-distance walk. Nothing will guarantee you blisters faster than walking in brand new, stiff boots and sometimes a certain make will disagree with your feet more than others. You should also try and ensure they are laced properly and tightly so your foot does not move too much inside.


  • Good walking socks are also important and if your boot is loose for whatever reason then doubling up on socks can help fill the boot and prevent movement as above. Wearing thin liner socks inside thicker walking socks helps reduce friction and is a standard recommendation – the military even pioneered a double-layered ‘1000 mile sock’ for this purpose – however some people (and many service personnel) find this actually causes them more blisters.


  • Preventing Moisture – whether caused by sweating or getting your feet wet – is another common cause of blisters. Some people use astringents to keep their feet dry (talcum powder being the most common) but during the walk you will need to consistently re-apply them to maintain this. Keeping your socks dry is more important; carrying a second dry pair of socks and changing them when your first pair get wet will go a long way to preventing blisters.


  • Preventing excessive dryness – this can also lead to increased friction, although it is rarer, and some people use lubricants like Vaseline at the start of their walk. As above though these require re-application on a regular basis. Perhaps more important is the need to stay hydrated, as dehydration can cause a build-up of salt crystals on your skin which will increase friction (also a good tip for those prone to chafing).


  • Plasters – If you know you are prone to blisters then applying a blister plaster or tape (such as moleskin) helps provide another layer of protection against friction directly over your skin. Likewise, during your walk, if you start to feel heat in a certain area of your foot (known as a hot-spot) and can see a redness developing then applying a plaster will decrease your chances of developing a full-blown blister. However, over any extended time, plasters or tape usually come unstuck or become bunched and can actually cause more friction.


  • ENGO Patch –  One recent innovation in this area is the ENGO patch, which sticks to the inside of your shoe or boot and can be placed wherever you are most prone to blisters. Long-distance runners are starting to use them as they last much longer stuck to the footwear than traditional blister plasters or tape do when stuck to skin. Currently information on the efficiency of these is limited however and they are still quite expensive.


  • Post Walk – One last area of preventative action is your footcare post-walk, especially important if you are a regular walker or are attempting a long-distance trail. Soaking your feet and moisturising them can help keep the skin supple and reduce the impact of shear, with added benefit for your tired foot muscles after a long trod. Cutting your toenails can also be a useful preventative tool. An older school of thought was to deliberately cultivate callouses, hard patches of skin that develop through regular use and on which it is difficult to develop a blister (mainly because this skin is already damaged). A lot of regular walkers will develop these naturally and they do serve a purpose, however callouses (especially round the edges of the hard skin) can be very painful and if left to become too severe will cause further pain and changes to your bio-mechanics.


To Pop or not to Pop?


If you do develop blisters there are a few things you can do to help yourself, especially if you are due to walk a long distance the following day. A few of the methods above can help; soaking and moisturising being the best alongside applying tape/plasters and lubrication over the blistered area either before or during your walk. Another recent innovation has been Hydrocolloid dressings, which now come in plasters that you can apply over your blister and which aid the recovery process. Trying to avoid wearing shoes in the evening and effectively resting and airing your feet should help as well. If the blister is small it will heal quickly and may even be less painful by the next day.


However, a debate still rages over whether popping a blister and releasing the fluid (thus reducing the surface area and edges of the blister) is a good or bad thing. The main reason it is considered bad is that a popped blister is much more prone to infection (and an infected blister will probably mean an end to your walk and a trip to hospital). The blister is, after all, performing a function and should be left to do so if possible. However, with a large serum-filled blister the pain can be quite intense making walking of any kind difficult and releasing the fluid may be appropriate. Be sure to clean the blistered area with an alcohol swab or similar and if possible sterilise the needle or pin you are using (if you can, use a packaged and sterile hypodermic needle or scalpel blade but these are hard to come by). Be sure to lance the blister (creating two holes one on entry and exit) and then cover the blister after further sterilisation as above.


More Information

We hope you have found this article useful and if you would like to do any further research then please find attached some useful links:


About the Author

Ed Terry is a qualified Mountain Leader who has been working as an outdoor instructor both guiding adult groups and working with young people in schools or on overseas expeditions. An accomplished traveller, Ed discovered a love for trekking in the canyons and mountains of South America and has since applied this to the hills and trails of the UK. He is a passionate environmentalist and can often be found mending footpaths, dry-stone walling or running educational sessions on conservation issues.