What Does Melanoma Look Like? 5 Warning Signs to Watch For

Learn the ABCDEs of melanoma so you can spot potentially cancerous moles.

Melanoma is the deadliest form of skin cancer. If you spot the warning signs of melanoma early, it's often highly treatable. That's why it's important to know what melanoma can look like.

Melanoma sometimes starts with changes in a mole. There are several ways to tell the difference between a suspicious mole and a normal one. Here's how.

What a Normal Mole Looks Like

Moles are common skin growths in which pigment cells have grown together. Most adults have between 10 and 40. They usually appear by late childhood and pop up until around age 40. After that, they typically fade.

You usually have them above your waist or where your skin is exposed to the sun. You typically don't find them on your scalp, buttocks, or breasts.

Normal moles usually have the following features:

  • Smaller than about 1/4 inch, the width of a pencil eraser
  • Round or oval
  • Smooth surface
  • Distinct edge
  • Dome-shaped
  • Even color (usually pink, tan, or brown)
  • Darker on people with dark skin or hair

Why It's Important To Notice Mole Changes

Melanoma is one of the easiest cancers to catch early because it shows up on your skin or the lining of your mouth or nose. Checking your skin regularly helps you notice changes to your skin or moles, early signs of skin cancer.

Spotting cancer early means you can treat it more effectively. There's also less chance of disfigurement. The less time melanoma has to spread, the less area it will likely cover (less to remove later).

It's also better to treat cancer in earlier stages because some later-stage cancer treatments can affect your health for a long time. Finding out about melanoma early also means fewer invasive treatments and less risk of long-term side effects. It's less expensive.

How To Prevent Melanoma

You can't entirely prevent melanoma. Some factors are out of your control, like your age, family history, or having light skin, hair, or eyes. But you can control other factors, like your habits.

The American Cancer Society (ACS) recommends:

  • Watching out for abnormal moles
  • Checking your skin regularly
  • Avoiding anything that could weaken your immune system
  • Not using tanning beds and sunlamps

Limiting sun exposure is one of the best ways to avoid melanoma.

Here are some tips for when you go out in the sun:

  • Stay in the shade as much as possible.
  • Wear a shirt, sunscreen, hat, and sunglasses.
  • Make sure children practice sun safety, too.

How You Can Check Yourself for Melanoma (With Examples)

You can perform a skin cancer self-exam in 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.

ABCDE stands for:

  • Asymmetry
  • Borders
  • Color
  • Diameter/dark
  • Evolution

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.


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



Uneven, squiggly edges can be a sign of early melanoma. The edges could be notched, ragged, or blurred. The pigment may even spread out into the skin.



Check for subtle shading differences within the mole or colors other than brown or black, like red or blue. Benign moles are usually all in one shade, whether pink, tan, or brown. Atypical moles may have gray, white, pink, blue, or a mix of shades.



A mole 1/4-inch across or larger should catch your notice. It could be a sign of a cancerous mole. If it's already reached this size, it may be a more advanced case of melanoma. It could also be benign, so talk with your healthcare provider about it as soon as possible.

"D" also stands for dark. In recent years, many healthcare providers and healthcare organizations decided to change the D in ABCDEs to "dark" to describe melanoma spots.

This is true even for people with dark skin because melanoma often appears on less-pigmented skin, such as hands or feet. Many healthcare providers think the darkness of the spots is a more reliable indicator than the diameter.



Any changes—in size, shape, color, or more—can be signs of melanoma. Benign moles usually look the same over time. Atypical moles may change over weeks or months. If you check your skin regularly, you'll notice changes sooner.


A Quick Review

It's essential to spot the warning signs of melanoma early. This skin cancer is highly treatable, especially in the beginning stages.

Although you can't prevent it entirely, one way to catch it sooner is to check your skin regularly. Be on the lookout for any changes to moles or spots. Remember ABCDE: asymmetry, border, color, diameter/dark, evolution.

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8 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Cancer Institute. Common moles, dysplastic nevi, and risk of melanoma.

  2. Wensley KE, Zito PM. Atypical mole. In: StatPearls. StatPearls Publishing; 2023.

  3. Petrie T, Samatham R, Witkowski AM, Esteva A, Leachman SA. Melanoma early detection: big data, bigger pictureJ Invest Dermatol. 2019;139(1):25-30. doi:10.1016/j.jid.2018.06.187

  4. American Cancer Society. Risk factors for melanoma skin cancer.

  5. American Cancer Society. Can melanoma skin cancer be prevented?

  6. American Cancer Society. How do I protect myself from ultraviolet (UV) rays?

  7. Skin Cancer Foundation. Ask the expert: Why have your "ABCDEs" for the warning signs of melanoma changed?

  8. Goldsmith SM. A unifying approach to the clinical diagnosis of melanoma including “D” for “Dark” in the ABCDE criteriaDermatol Pract Concept. 2014;4(4):75-78. doi:10.5826/dpc.0404a16

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