What does it mean when your toenail turns black?

There are several reasons why toenails may turn black, which is medically known as "melanonychia." Here are a few possible causes:

1. Fungal Infection:

- A common cause of black toenails is a fungal infection, particularly onychomycosis. When fungi invade and grow under the nail, it can lead to discoloration.

2. Trauma:

- Injury to the toenail, such as dropping something heavy on the foot or stubbing the toe, can cause bleeding under the nail. This blood can accumulate, leading to a black appearance.

3. Subungual Hematoma:

- A subungual hematoma occurs when blood collects beneath the nail. It can happen due to trauma or underlying medical conditions that affect blood clotting.

4. Melanoma:

- In rare cases, a black toenail may indicate a type of skin cancer called melanoma. This type of cancer can occur anywhere on the body, including the nail matrix, which produces the nail. However, melanoma under the nail is less common than other causes of black toenails.

5. Other Medical Conditions:

- Some medical conditions, such as diabetes and certain medications, can cause discoloration of the toenails.

It's important to note that black toenails are not always a cause for concern and may resolve on their own. However, if the discoloration persists, there is pain or other concerning symptoms, it's advisable to consult a healthcare professional, such as a dermatologist or a podiatrist, for evaluation and appropriate treatment.