Have you ever wondered what caused your toenail to become thick, black, white, yellow or any discoloration? Here’s the description of many causes that can cause your nail to be discolored. An evaluation by foot and ankle specialist is vital to establish the proper diagnosis. Visit our podiatrists for a complete evaluation of your toenails and treatment options.
Yellow discoloration in the toenails is commonly caused by fungal infection. The fungus often develops underneath the nail, resulting in it becoming thick, raised and yellow in color.
Other potential causes for yellow discoloration of the nail include diabetes mellitus and lymphedema (chronic leg swelling). Yellow staining of the nails can also occur in individuals who use nail polish. A stained nail may take several months to grow out.
Toenails will often become thick as an individual grows older. Thickening may also occur as a result of trauma to the toenail, such as when it repeatedly hits the end of a shoe that is too short. Sometimes when something is dropped on the toenail, the nail will fall off. When a new toenail grows back, it will often be thicker than it was previously.
Thick toenails can also be seen in individuals with nail fungus (onychomycosis), psoriasis and hypothyroidism.
White toenails can develop for several reasons. Trauma, such as when an object is dropped on a toenail, often causes bleeding under the nail because of broken blood vessels. This would cause a black toenail. If the trauma does not cause broken blood vessels, a white spot may appear under the nail. The spot will slowly grow out with the normal growth of the toenail.
Sometimes white lines appear within the toenail. These may be caused by recurring trauma, such as when a runner wears shoes that are too small and the toe hits the end of the shoe. White lines may also occur due to a medical illness or trauma that has occurred elsewhere in the body, causing protein to be deposited within the nail bed.
A fungal infection that affects the outermost layer of the toenail may cause a bright white discoloration of the toenail.
A white area close to the nail fold (the lunula) varies in size from one person to another. This is a normal aspect of the nail.
A black, purple or brownish discoloration under or involving a toenail is frequently due to trauma to the toenail, such as when something is dropped on the toe. The color results from a blood clot or bleeding under the nail and may involve the entire nail or just a small portion of it. This can be very painful when the entire nail is involved and may need medical attention to relieve the pressure caused by bleeding under the toenail.
When the second or third toenails are involved, it is commonly referred to as “runner’s toe.” This can be the result of the nail being slightly too long and the shoe being either too big or too tight. If the shoe is too big, when running down hill, the foot slips and the nail can get caught where the toe cap meets the toebox. If the shoes are too tight, the nail can get pinched and jammed, resulting in bleeding between the nail plate and nail bed.
Although it is very rare, a more serious cause of black toenails is malignant melanoma. Since early diagnosis and treatment of melanoma improves the chances for a good outcome, it is important that all black toenails be evaluated by a qualified foot and ankle surgeon to rule out this cause.
Other rare causes of black toenails include fungal infections, chronic ingrown nails or health problems affecting the rest of the body.