One of the most common questions on online ultra email lists are those about toenail problems, mainly blood under the nail – black toenails. I am often puzzled by these questions because, in my mind, it’s pretty basic stuff.
It’s easy to assume your toenails are fine. You trim them once a month. You really don’t understand the relationship between toenails, socks, toeboxes, and how the foot moves inside the shoe.
First, look at the picture. This runner has thick toenails. Most likely because of a continued loss of earlier toenails. The toenails are not filed down and are too long. I worked on this runner’s feet and was surprised that he did not have worse problems.
Let’s start with trimming toenails. How hard can it be to trim your toenails? I guess for a lot of folks, it’s a huge deal and something they have a hard time doing. In all the years I have been patching feet, I have observed that untrimmed toenails are the number one cause of problems leading to toe blisters and black nails. Socks catch on nails that are too long or that have rough edges. This puts pressure on the nail bed, leading to blisters under the toenails, at the tips of the toes, or painful toenails as they are pushed back into the cuticle. Nails that are too long are also prone to pressure from a toebox that is too short or too low.
Toenails should be trimmed regularly, straight across the nail-never rounded at the corners. Leave an extra bit of nail on the outside corner of the big toe to avoid an ingrown toenail. After trimming toenails, use a nail file to smooth the top of the nail down toward the front of the toe and remove any rough edges. If you draw your finger from the skin in front of the toe up across the nail and can feel a rough edge, the nail can be filed smoother or trimmed a bit shorter. Remember though, the shorter you trim your nails, the greater the likelihood that you will experience an ingrown toenail. Conversely, nails that are too long can rub against the front of your shoes and catch on your socks, which can lead to a black toenail, wear holes in your socks, cut into other toes, and crack the nail when you run downhill. Shoes that are too tight in the forefoot or too short can cause the nail to press into the sides of the toe.
Use an emery board nail file from your drug store. Better yet, invest a few bucks in a nice metal file that will last a long time and serve you well. If you need clippers, there are regular large clippers and for thick nails, and nippers and scissors made exclusively for toenails. If your local drug store or pharmacy doesn’t have them, check out www.FootSmart.com for a great selection.
When you run or walk, your foot moves forward as it moves onto the toes. The toes bend as the toebox bends, moving to the end of the toebox. Many runners’ toes make contact with the front or top of the toebox, and the toes, over time are traumatized. The nail is jammed backwards. Bit by bit, the nail takes a beating and blood forms under the nail or on the sides or bottom of the toe. Toes with long nails or rough nail edges, or Morton’s toes (2nd toe longer than the big toe), will often blister.
A little bit of care in toenail trimming goes a long ways in preventing toe blisters and black toenails, and in making your socks last longer.