The different causes of toenail splitting generally include irregularities in toenail growth, some types of toenail injuries, and certain nutritional deficiencies that can lead to toenail abnormalities. Unevenly-trimmed nails and sensitivities to the chemicals in nail polish can also increase the chances of toenail splitting in some people. Some medical conditions such as anemia or thyroid problems can affect toenail health as well. Many cases of toenail splitting can be resolved with certain home remedies, although persistent and frequent nail splits may require a doctor's care.
Toenails that are trimmed and filed poorly usually are at increased risk of splitting as well as of turning into painful ingrown nails. Nail technicians generally recommend that toenails be cut in a straight line and rounded carefully at the edges. Toenail splitting can also sometimes result from frequent use of nail polish and polish remover containing high amounts of isopropyl alcohol. This chemical often pulls needed moisture from the nails and can lead to horizontal splits between the different nail layers.
Injuries are also common causes of toenail splitting, particularly in people who engage in sports such as soccer or long-distance running. These kinds of splits often occur in the big toe and are accompanied by bruising and swelling in cases of hard impact. Split toenails from this kind of injury often heal effectively on their own as long as the splits are kept clean to prevent infection.
Certain dietary factors can also lead to toenail splitting. People who are otherwise healthy sometimes do not get enough regular vitamin A, iron, or protein in their diets. They are often more susceptible to brittle and split nails as a result. Adding vitamin supplements and healthier foods to a diet on a daily basis usually strengthens nails and prevents further splitting. Drinking the recommended amounts of water per day and using nail moisturizers can also help prevent more toenail splitting in these cases.
Some people who experience persistent and severely split toenails sometimes have more serious underlying health conditions as root causes of this nail problem. Imbalances in the thyroid, iron-deficient anemia, and certain kidney disorders can often cause split toenails. Sufferers who do not see improvements from diet changes or increased hydration may need to see a physician who can test them for any of these conditions. Once they receive a proper diagnosis and treatment, the split nails usually improve over time along with the other symptoms.