No one is immune to blisters. Blisters often curse a hiking trip, even those trips that are just a few miles over flat terrain. During a hike, a small, tiny blister often grows into a swollen, painful menace—resulting in a miserable hiking trip as the hiker limps awkwardly home. However, blisters are preventable if you understand the conditions that cause them and they will heal faster if you know how to treat them properly. In the following article I begin by explaining what blisters are why they occur. I then discuss techniques to prevent them from occurring, followed by guidelines for treating blisters that will expedite the healing process.
What Causes Blisters?
Blisters can be caused by burns, allergic reactions, and fungal infections. The most common cause of blisters resulting from hiking is friction. When your feet get hot and sweaty, your socks stick to your feet and begin to rub against the inside of your shoes or boots. The skin at the point of friction becomes red and irritated. Lymphatic fluid flows to the friction site gathering between the layers of skin to protect the area like a small balloon, eventually forming a bubble of fluid known as a blister. Blisters can also occur when your socks, boots or shoes get wet from the rain, snow, or a stream crossing.
The key to preventing blisters is to eliminate friction. Shoes and boots should be well broken in and you should make an effort to keep your socks as dry as possible by changing them when your feet get hot and sweaty or by taking your shoes or boots off periodically to let your feet and socks dry out when you take a snack break. Preventing blisters requires both well-fitted hiking boots and the use of quality hiking socks. It does no-good to hike in a $300 pair of boots while wearing a cotton sock. And it does no-good to hike in a poor-fitting boot while wearing the best hiking sock available. Avoiding blisters starts with using a well-fitting boot and a dedicated hiking sock. If this means bringing along one or two extra pairs of socks, it may be well worth a few more ounces of pack weight.
If you expect to do a lot of stream crossings you should consider bringing along a pair of sandal or crocs to wear instead of your boots to keep them dry. Bringing along a pair of camp shoes also gives your boots and socks an opportunity to dry for a longer period of time before you need to put them back on again. Conditions permitting, you may also want to re-evaluate a preference for leather hiking boots. Ultralight hikers who wear lightweight boots, running shoes or even sandals may experience less blisters because their footwear dries more quickly when it gets wet. Gore-Tex lined leather boots, on the other hand, can take days to dry out completely.
Other effective ways to reduce friction include applying petroleum jelly to a hot spot or sprinkling foot powder or corn starch on your feet to prevent moisture buildup. If you feel a hot spot forming on your feet, you should stop to inspect it immediately and apply moleskin or tape to prevent it from turning into a blister later in the day. Some hikers also prefer wearing two sock layers, a liner which absorbs moisture and can be changed frequently, and a heavier outer sock. This moves the site of friction between the socks, away from your skin and a sock.
The Importance of the Hiking Sock
While I lack data to prove my suspicions, I strongly suspect the leading cause of blisters among hikers is from the use of poor fitting or simply the “wrong type” of sock. Before examining methods to adjust hiking boots to avoid blisters, it is crucial that a hiker uses the right sock. After all, it is the sock—not the boot—that lies against the skin. And it is the rubbing of the sock against the skin that causes blisters.
Say No to Cotton Socks
Rule #1 when it comes to socks for hiking is to always wear dedicated hiking socks. Never use cotton socks. Period. Using cotton socks for hiking is so bad that hikers have a better chance to avoid blisters by not using socks at all than by wearing a cotton sock. Yes, cotton socks are THAT bad.
Why are cotton socks so terrible? Cotton socks are awful for hiking because they quickly get wet (cotton holds and absorbs sweat), bunch up inside the boot and then rub against the hikers skin. Remember, the sock rubbing against the skin is what causes blisters. Dedicated hiking socks, such as those made by Smartwool, Thorlos & Wigwam, substantially reduce or eliminate this problem.
The Many Benefits of Hiking Socks
First, dedicated hiking socks provide significant additional padding for the feet—particularly in high impact areas (such as the heel, ball of the foot, and the top of the foot below where the boot is laced). This padding, besides helping prevent blisters, also significantly increases comfort and alleviates the “sore foot” problem often encountered on longer hikes or hikes through rocky terrain.
Second, dedicated hiking socks are made from various natural (Smartwool) or synthetic (Thorlos & Wigwam) materials that do NOT absorb water. Instead, hiking socks transfer water from the foot into the fabric of the boot (where it will then dissipate if the boot is a quality breathable hiking boot). In short, a dedicated hiking sock keeps the hikers foot dry by letting the foot breathe. And a dry foot is a necessity for blister-free hiking.
Finally, hiking socks are thicker and much stronger than cotton socks. Even the thinnest hiking socks will not “bunch up” inside the hiking boot (with cotton socks, having the sock “bunch up” by the toes is a common problem and often leads to nasty blisters not easily treated along the trail).
Blisters come in different shapes and sizes. The first stage in determining how to treat a blister is to assess it. Broken blisters that are leaking fluid should be disinfected and bandaged. Unbroken blisters that are painful should be pricked with a sterile needle and drained. Small blisters that are not painful should be left alone because the best protection against infection is the blister’s own skin. These will heal by themselves and will be reabsorbed in a few days.
If a blister has broken, it should be cleaned, disinfected and then bandaged. You can disinfect the would by irrigating it with chlorinated water, wiping it with an alcohol swab, or rubbing it with a dab of Purell. If the skin over the blister is ragged and dirty it should be carefully cut off. Otherwise it should be left intact to prevent infection. Before bandaging the wound, an antibiotic ointment should be applied. Research has shown that the application of Neosporin or triple antibiotic gel will kill off infecting bacteria after two applications and accelerate the healing process.
Unbroken blisters that are painful should be drained. This is caused by the build up of fluid in the blister, so removing it will help relieve the pain. First swab the blister with alcohol to disinfect the area. Then, using your fingers, push the fluid to one side of the blister. Prick the side with the fluid using a needle that has been sterilized by alcohol, a lighted match or in boiling water. The needle should prick the blister horizontally at the point where the blister begins to rise above the skin. Leave the skin overlying the blister in place to prevent infection. Apply antibiotic gel to the site of the needle pricks and cover with a bandage. For small blisters, cover the entire blister with an adhesive bandage. For larger blisters cover the entire blister with a porous, plastic-coated gauze pad that will absorb any further drainage and allows the blister to breath and dry out. If the bandages get wet, reapply the antibiotic ointment and redress the blisters. After a few days, the skin under the blister should have healed and you can cut away the remaining dead skin.
Other Treatments For Blisters
If you hang around long distance hikers and backpackers long enough, someone will suggest using Superglue to help heal a blister or make it possible to keep walking with one. This suggestion is actually a lot less far-fetched than it sounds. Superglue is widely used by surgeons to bond together organs or parts of the body that respond poorly to stitches. It is also effective in closing skin shears like cracked calluses where the sides of a wound must be bonded to accelerate healing.
Superglue can be used to treat blisters by squirting it between top of a popped blister and the skin beneath it. This bonds the roof of the blister to the underlying skin reducing the risk of infection and creating a hardened shell over the blister site. The downside of this technique is that the solvents in the Superglue will hurt like hell when they are applied to the wound. To be on the safe side, make sure that you have sterilized the blister with alcohol before applying Superglue to it.
Tincture of Benzoin is another bonding agent that can be also be used to seal the roof of the blister to the exposed skin underneath. It already contains alcohol, so a separate application is unnecessary.