Black Toenail Here s What it means

1. Bruising under the nail (subungual hematoma)

• One of the most common causes.
• Can happen after:
  • Stubbing your toe
  • Dropping something on it
  • Running or wearing tight shoes
• Blood collects under the nail, causing a dark red, purple, or black appearance.
• The discoloration usually grows out as the nail grows.

2. Repeated pressure or friction

• Tight footwear, long walks, or sports can repeatedly injure the nail.
• This is common among runners and hikers.

3. Fungal infection

• Some fungal infections can cause nails to become dark, thick, brittle, or discolored.
• They may also cause yellow, white, or brown changes.

4. Certain medications or health conditions

• Some conditions and medications can affect nail color or growth.
• A healthcare professional can help determine the cause.

5. A dark streak or spot from pigment changes

• A brown or black line under a nail can sometimes be caused by increased pigment.
• Rarely, it can be a sign of subungual melanoma (a type of skin cancer under the nail).

When to get it checked

See a healthcare professional or dermatologist if:

• The black mark appears without any injury
• The discoloration is a new dark stripe or spot
• It is growing, changing shape, or spreading onto the surrounding skin
• The nail is painful, swollen, or bleeding
• The color does not move outward as the nail grows

A photo and details such as how long it has been black, whether there was an injury, and whether it is a spot or a full nail change can help narrow down the likely cause.