How do I check moles for melanoma?

Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
Here's my 10-second skin cancer test. You'll need a number 2 pencil with an unused eraser. Check your most obvious moles against the eraser head by using this ABCDE guide:

A: Is it asymmetrical? (The eraser head is symmetrical and the mole should be too.)
B: Is the border as clearly defined?
C: What color is it? Color should be brown or black and consistent.
D: Diameter should be no larger than the eraser.
E: Pay attention to its evolution. Make it a habit to check your birthday suit on your birthday, including nails, scalp and toes.

If you're concerned about a mole after trying this test, take a picture of it. Put a ruler up next to it when you take the picture. Then place the picture on your calendar and measure it again every month to see if it's changing. If so, see your dermatologist immediately.
This content originally appeared on
When checking moles for melanoma skin cancer, the ABCDE method can help you remember what skin changes to look for.
  • Asymmetry: If you draw a line through the mole, the halves do not match.
  • Border: Borders are uneven, maybe scalloped or notched.
  • Color: Several colors are present in the mole, such as shades of brown, tan, and black. The mole could also turn blue or red.
  • Diameter: larger in diameter than the size of a pencil eraser (1/4 inch)
  • Evolving: Any changes to a mole are a warning sign, including changes in size, color, and shape or if it becomes itchy or bleeds.

Continue Learning about Skin Care

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.