The most common causes of discolored toenails are fungal and bacterial infections, but bruising and bleeding under the nail might also be to blame. In some cases discoloration is an indication of a much more serious condition, like diabetes, liver failure, or heart disease. Many doctors and care providers make an effort to examine patients’ nails during routine check-ups to monitor for problems that may first appear as color variation in the finger or toenails.
Fungal Infections
Toenails that are yellow or have a chalky look often indicate a fungal infection. Fungi are small strains of mold or other parasitic cells that invade a host and essentially use it as a breeding ground. When these cells get into the toenails, they often cause the nails to turn yellow or brown, depending on the variety or particular strain involved. At first the discoloration is usually very small, often appearing just as a dot on the surface of the nail. If things are allowed to progress, though, all nails on one or both feet might change color and even shape, often dramatically.
Fungal spores are pretty common, and they’re found in most places, from soil and dust to food and waste. Warm, moist, and humid environments cause them to thrive, and as a result pools, shower rooms, and public bathrooms pose an increased risk, particularly to people who walk barefoot through them.
Some footwear can also increase a person’s chances of infection. Regularly rotating shoes can reduce the chances of developing an infection that might cause discolored toenails, and people who are very concerned about infection might go so far as to select shoes that are vented or that otherwise allow air to flow in order to prevent moisture from collecting.
Bacterial Problems
Bacterial infection also can discolor toenails, and nails with this sort of infection will typically soften and take on a green color. Advanced infections also might cause the nail to lift from the nail bed. Bacterial infections are a little bit different from fungal growths because they are something that has actually caused otherwise healthy cells to become diseased, whereas a fungus is something foreign that has taken up residence and growth alongside the body’s regular functioning.
People usually catch bacterial infections in different ways, too. In most cases, these happen as a result of an injury or trauma that has left part of the skin or nail bed exposed to outside elements. A smashed toe that isn’t properly bandaged is one example; a pedicure that clips too much of the delicate cuticle tissue or that breaks the skin under the nail is another. Strains of bacteria typically enter through broken skin, then begin invading the toenail and surrounding tissues.
Trauma and Bleeding
Toenails that are black may indicate a hematoma, which is essentially pooled blood. This most frequently happens because of a stubbed toe, something heavy that has been dropped on the foot, or an ingrown toenail. These will usually go away on their own after a time, though it can take a few weeks for the trapped blood to be broken down and absorbed by the body. This sort of injury often looks unsightly, but isn’t usually a cause for major concern. Any blood that doesn’t go away, as well as spots that seem to be growing larger instead of shrinking, should usually be checked out by a medical professional, though, as these could indicate circulatory or other blood problems.
As a Symptom of Other Conditions
Minor discolorations or changes in color and texture that happen slowly over time might be an indication of a much more serious medical condition. Diabetes and several liver ailments can cause color changes in the finger and toenails, for instance, as do heart disease and some forms of kidney failure. Systemic conditions like anemia and lupus might also be to blame. In these cases nail changes are usually just one of many different symptoms throughout the body, but they are often an easy place to start.
Most medical experts recommend that anyone who notices changes in their toenail coloring, no matter how minor it may seem, get the problem evaluated to rule out serious conditions. If problems are noticed treatment can start right away. The earlier these and other problems are identified, the easier most are to cure.
