What Does Melanoma Look Like? 5 Skin Cancer Signs to Watch For

Melanoma is the deadliest form of skin cancer, but it's often treatable if caught at an early stage. That's why it's important to know the early signs of melanoma, which usually starts as a mole or other suspicious skin spot.

You can perform a skin cancer self-exam in just 10 minutes if you know what to look for. All you need to do is memorize five warning signs, called the ABCDEs of melanoma, which can help you distinguish between normal skin markings and what could be signs of a cancerous mole.

In these photos, courtesy of the Skin Cancer Foundation, the first example for each set is what doctors would probably consider normal skin. The second is an example of something that could be a warning sign of melanoma.

Asymmetry

If you drew a line down the middle of a spot that could be melanoma, the two sides wouldn't match.

Borders

Uneven, squiggly edges can be a sign of early melanoma.

Color

Check for subtle shading differences within the mole, or colors other than brown or black, like red or blue. Benign moles are usually all one shade of brown.

Diameter

A mole 1/4-inch across (about the size of a pencil eraser) or larger should set off red flags. It could be a sign of a cancerous mole.

Evolution

Any changes—in size, shape, color, or more—can be signs of melanoma. Benign moles usually look the same over time.