Health library

Skin cancer signs

Checking your skin can help you spot skin cancer early. Your doctor can tell you how often to do a check.

The ABCDEs of melanoma

Melanoma is the most deadly form of skin cancer. These ABCDEs can help you tell if you should see a doctor about a mole or a spot. Even one of these signs is a reason to see a doctor immediately.

1. Asymmetry. Half the mole or spot is unlike the other half.
2. Border. The mole or spot has an irregular, scalloped or poorly defined border.
3. Color. The color changes from one area of the mole or spot to another. It may have shades of tan, brown or black, or it could be white, red or blue.
4. Diameter. The mole or spot is larger than a pencil eraser. Melanomas are usually larger than 6 millimeters (about ¼ inch) when diagnosed. They can be smaller though.
5. Evolving. The mole or spot looks different from others on your body or is changing in size, shape or color.

Source: American Academy of Dermatology