Medical questions & health advice by board certified doctors
"What causes dark coloring underneath the toe nail?"
Why do I have a dark blotch, about the size of a dime, spreading underneath my toenail. It doesn't look like blood, and I don't think I damaged it in any way - it's just weird because I've neve rseen anything like this. Is it a sign of some kind of underlying disease that I should know about?
There are several things that can cause changes in the color of the nails, and some of them require medical evaluation. The doctors who will be well qualified to discuss this issue include your primary care doctor or your dermatologist. By far the most common cause of changes in the color of nails in healthy individuals is trauma. When the nail is traumatized, blood can leak out from the tissue and collect in the nail bed. This can cause pain and discoloration. However, in the absence of discomfort and a history of trauma, this is less likely. Another very common cause of nail color changes is a fungal infection. Fungal infections of the nails can begin quite insidiously, but eventually result in changes in color of the nail as well as distortion and thickening of the nail itself. Most will require treatment with oral antifungal agents as prescribed by your doctor. Occasionally, melanoma, which is a serious form of skin cancer, can present as a dark spot under the nail. For this reason, most new spots should be checked out by a doctor. As always, the diagnosis and the management of your particular condition will require a physical examination by your personal physician. Scheduling an office visit with your primary care doctor or your dermatologist is recommended.
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