Why is your big toenail black?

A black toenail can have several causes, some of which are harmless while others may require medical attention. Here are a few common reasons why a toenail may turn black:

1. Trauma: If you stub or drop something heavy on your toe, the nail can become bruised and appear black. This type of black toenail is usually not a cause for concern and should resolve on its own as the nail grows out.

2. Fungal infection: A fungal infection of the nail, also known as onychomycosis, can cause the nail to thicken, become discolored, and even turn black. Fungal infections are common and can be contagious, so it's important to seek treatment from a doctor to prevent it from spreading to other nails.

3. Melanoma: In rare cases, a black toenail can be a sign of melanoma, a type of skin cancer. Melanoma can appear as a dark streak or spot on the nail and may be accompanied by other symptoms such as changes in nail shape or texture. If you notice any concerning changes to your toenail, it's important to see a doctor for evaluation.

4. Other medical conditions: Certain medical conditions, such as diabetes and peripheral artery disease, can also cause changes in nail color, including black toenails. If you have a chronic medical condition and notice a black toenail, it's important to consult your doctor to rule out any underlying health problems.

If you have a black toenail and are concerned about the cause, it's best to consult a healthcare professional for proper evaluation and diagnosis. They can determine the underlying reason for the black toenail and recommend the appropriate treatment if necessary.