Bruised Toe Nail
Toe nails are a thin plate of protein material called keratin, the same material that makes up your hair. Their two primary purposes are to protect the toes from injury and to help provide the shape of our toes. The average toe nail takes 6-12 months to grow out completely, or about twice as long as a fingernail. Bruised toe nails are an accepted consequence of running. No one is immune.
What causes bruised toe nail?
The most obvious cause of a bruised toe nail in a runner is the result of improper shoe size. Shoes that are either too small or too narrow can increase the pressure on the toe. But that’s not the only shoe problem that can cause bruised toe nails. Often overlooked is shoes that are too big. Runners often select shoes slightly bigger than their normal, everyday shoes in an effort to minimize toe contact with the inside of the shoe. However, take too far this will lead to a foot that slides around in a shoe and leads to bruised toe nails.
Another and more common cause of bruised toe nails is the result of the forces exerted on the toes with each step. These forces are estimated to be approximately three times body weight with each step. A portion of those forces is transferred to the toes. The pressure inside each to increases and then dissipates when the toes come off the ground. This cycle is repeated thousands of times when we run. Try this simple example to help illustrate this process. Press your thumb and index finger together and notice the blood blanch out from the finger tips. Then release the pressure and watch the color return. This same process occurs in your toes with every step you take while running. The repetitive trauma of running on toes, either form the sole of the shoe or the top of the shoe, causes bruising to occur underneath the toe nail.
Treatment
The treatment for a bruised toe nail is often surveillance. The toe nails will continue to grow and the bruise will simply move toward the end of the toe and eventually be removed as you clip your toe nail. We recommend removing any loose sections of toe nail to prevent it from toggling around while you run. A file is often helpful to reduce the nail thickness. There is an exception to the surveillance method and that involves situations in which a blister forms under the toe nail. In these cases, the blister fluid should be drained. This is accomplished in the clinic with an electric cautery tool that burns a hole through the nail and releases the pressure of the blister. At home, a paperclip can be heated with a lighter or match and uses in a similar fashion. Care should be exercised to avoid injuring the nail bed under the toe nail. When in doubt, let a qualified medical professional take care of this for you.
When to seek medical care
Anytime the skin around the nail becomes painful, swollen or red, looks infected, or if drainage appears, medical treatment should be sought. Those with certain health conditions, such as diabetes, should also seek care for even minor nail problems. Prompt medical care can often help patients avoid costly or painful procedures down the road. If the toe nail remains thick, a medical professional can provide treatment options to reduce the nail thickness. An important situation to seek medical care is if the bruise increases in size and does not grow out with the toe nail. Although rare, malignant melanoma is can occur under a toe nail. When in doubt, have it looked at.
Prevention
The prevention of bruised toe nails begins first and foremost with properly sized shoes. There are pads and caps available which are lined with a soft silicone to cushion the toes. This has been show to help some runners. In the end, bruised toe nails are an unfortunate consequence of running.
This information is not intended to diagnose, treat, or prevent any injury or disease. It is intended to serve as an overview of running-related injuries and should not be used as a substitute for sound medical advice from a doctor or therapist.
