Toenails are attached to the skin underneath them (the nail bed).
When a pushing force is applied to the end of the toenail, it moves the nail. Because the nail and nail bed are attached, shear will occur within the skin layers of the nail bed. And even the skin surrounding either of the four edges of the nail.
Take a close look at the blisters pictured here. If your nail is pushed repeatedly, let's say because your nails are too long or your foot is moving too far forward in the shoe, you can get a blister either:
Under your toenail (often blood-filled and commonly known as a black nail)
Around the nail (on either side of the nail, the base of the nail or at the end of the nail)
Or on the tip of the toe
Three of these toes have blisters involving the whole end of the toe!
Treating painful toenail blisters
When you get a blister, the upper layers of skin "bubble up" in order to hold the fluid being formed by the body. The skin expands as much as it needs too, to hold that fluid. On the other hand, blisters under the nail are much more painful. Think about the anatomy. You have the toe bone below, the rigid nail on top, and the very sensitive nail bed in between. As blood or blister fluid forms, it's stuck between a rock and a hard place, with no where to go. Pressure builds and significant pain is the result (a deep ache or throbbing) even when you're not on your feet. The only way to relieve this pain is to release the blister fluid. This usually requires drilling a hole in the nail. This can be done quite painlessly with the right equipment. Relief will be immediate.
If your toenail blister extends from under the nail to one or more of the four sides of the nail, the job is a lot easier. You can simply lance the blister by piercing the skin adjacent to the nail. This can be done easily, painlessly and cleanly with a sterile scalpel blade.
Causes of toenail blisters
There is more than one cause of toenail blisters. Understand the cause and you'll be able to prevent them. Let's look at 7 scenarios likely to lead to blisters around the nails.
Scenario 1: Shoes too small
This is obvious. When your shoes are too small and your toes hit the end, the nail is pushed back into the toe. And don't forget, swelling can make an otherwise well-fitting shoe too small.
The fix: You can tape or lube your toes 'til the cows come home, but you won’t stop a toenail blister if your shoes are too small. Other than cutting the toe out of your shoe, they're always going to be too small. There is no other way around it, you need new shoes.
If you're in a multiday event, you may need more than one pair of shoes to cope with swelling. It's common practice for ultrarunners to use 2 or more pairs of shoes of increasing size over the course of the race for this reason.
Scenario 2: Shoes too big
A shoe that's too big and loose will allow your foot to slide forward - there’ll be a gap behind your heel and your toes will hit the end of the shoe. This is almost as bad as having shoes that are too small. But there is one thing you can try before you throw them out.
The fix: Special lacing techniques help to keep your heel at the back of the shoe; stopping your foot sliding forward and toes hitting the end of the shoe. My personal favourite is the lace-lock technique http://youtu.be/LXjOLWgWq9k.
Scenario 3: Nail shapes and deformities
Some people have nails that are very thick. The higher they protrude upwards, the more likely they’ll be pushed by the top of the shoe. Others have normal nail thickness but the nail bed is elevated, causing the nail to be domed (pictured). And others have a toenail that is angled upwards (it’s not parallel with the toe). For different reasons the same thing happens - the nail is more likely to get pushed on from the shoe.
The fix: If the nail is thick, do your best to file it down. If you can't seem to get anywhere with it, see a podiatrist - we have a machine called a drill (which is basically a grinder) that painlessly thins even the thickest nails.
If your nail is not thick but it sits high (pictured), or it's angles upwards, it's a little more difficult to deal with and may take a surgical procedure to fix properly. If you're not keen on this and you want to find a conservative solution, you need to find shoes that are as deep as possible in the toebox to be able to accommodate the nail deformity – give the nail the room it needs.
Scenario 4: “Cocked-up” big toe
Some people have a hyperextended interphalangeal joint of the big toe - see the exaggerated crease in the middle of the toe (arrow). This "cocked-up" big toe results in the end of the toe, and therefore the nail, pointing upwards rather than being parallel with the floor. The toenail gets pressure from the top of the shoe and is pushed back into the toe with each step - if the shoe is not deep enough in the toebox.
The fix: This cocked-up position is a common consequence of the big toe knuckle (1st MPJ) being stiff. This stiffness may be functional or structural and each has a different fix.
A functional stiffness can be helped by a podiatrist. Depending on your mechanics, this may involve orthotics (with specific additions for the "functional hallux limitus" issue), heel lifts, calf stretches or a few other modalities, all aimed at improving windlass mechanism function. Have a look at the moving image. To start with, the toe is cocked-up at the end making the toenail angle upwards. But a simple piece of material under the the first bone of the toe makes it sit more level with the floor. This is just one example of what a podiatrist can do to change your foot mechanics to help you prevent toenail blisters of the big toe.
A structural (bony) stiffness is not so easy. Talk to your podiatrist about the options (different types of orthotics, footwear modifications, surgery if it's a big enough problem for you). Or do what you can to get shoes that are really deep in the toe-box to accommodate it. This can be easier said than done with running shoes. Ladies, consider buying men's runners - they are a bit deeper for the length.
Scenario 5: Clawed toes
Do you get blisters on your smaller toes (usually toes 2-5) because your toes bend downwards? This is called clawed toes. The tips of the toes sustain weightbearing pressure and that means the nail is pushed back into the toe with every step.
The fix: There are degrees of clawed toes. And there are different reasons for clawing.
Some people have perfectly straight toes but they claw only when walking and running. At the other end of the spectrum, toes can be in a fixed clawed position so you are walking right on the tip of the toe.
Either way, the aim is to stop you from walking on the tips of the toes, or at least to lessen the weightbearing pressure. This is what toe props do. Toe props take up the space under your toes and encourage your toes to sit straighter. Even if your toes are fixed, a toeprop will allow a spreading of the load to the under-surface of the toes, so there's not quite so much force pushing the nail back.
There are several forms of toe props. You can find pre-made toe props at the chemist (like this yellow one). And custom made toe props are made by a podiatrist (the pink one - watch the 48 sec video). Podiatrists can also help to identify if there are fixable reasons why your toes are clawing.
Toe props can be great for everyday use and they last a long time (usually a year or more - for the custom made ones). Runners (distance and multiday runners) will need to experiment to ensure the props are suitable for long durations. Most runners with toenail blister problems are wary of putting something foreign between their toes - the concern is the device itself will cause more problems than it fixes. This concern is warranted and while I can't say for sure whether a toe prop will work for you, I can show you how we make custom toe props and what they look like (they hold their shape but they are bendy at the same time). They're not expensive at all and for the potential benefit, I think they are worth a try. If nothing else, at least you'll have left no stone unturned in trying to get on top of your toenail blister problem.
If toeprops don't work, consider the silicone gel toe sleeves that are closed in at the end (available at most chemists). They will provide cushioning and apical shear absorption which is better than nothing.
Scenario 6: Downhill terrain
Running or walking downhill causes your foot to move forward in the shoe with more force and you're more likely to get toenail blisters than if you were on the flat or going uphill.
The fix: The lacing technique described earlier will help keep your foot back in the shoe. And modifying your gait so that your foot doesn't land too far in front of you will also help.
Scenario 7: Long, thick or rough toenails
When your nails are long, thick or rough, you just make all of the above situations worse.
The fix: Keep your nails short and thin and smooth. Neglect this and you're asking for toenail blisters. See a podiatrist if you need to - as I mentioned earlier, we have specialised equipment to help get your gnarly nails into much better shape and keep them out of trouble - and it doesn't even hurt!
Some causes of toenail blisters are easy to fix yourself - a bit of common sense and preparedness goes a long way. Others you might need some help with.
If you're getting blisters around your toenails in spite of your best efforts, see a podiatrist - we might be able to help!
And one last picture just in case you forgot how much it is worth avoiding these blisters ... from John Vonhof again at Fixing Your Feet.
Written by Rebecca Rushton
Rebecca is an Australian podiatrist with over 20 years experience. She has spent a lifetime dealing with her own blister prone feet in her sporting and everyday life. Rebecca specialises in helping athletes and sports medicine professionals figure out how to manage foot blisters with ease. And for kicks, she enjoys providing blister care at multiday ultramarathon events.
Rebecca is the founder of Blister Prevention and author of "The Blister Prone Athlete's Guide To Preventing Foot Blisters".