Checking your moles regularly at home takes about 10 minutes and can catch skin cancer at its earliest, most treatable stage. When melanoma is found before it spreads beyond the skin, the five-year survival rate is over 99%. That number drops to 76% once it reaches nearby lymph nodes and 35% if it spreads to distant organs. A simple routine of knowing what to look for and scanning your entire body can make a real difference.
What a Normal Mole Looks Like
Before you can spot something suspicious, it helps to know what healthy moles look like. A common mole is usually smaller than about 5 millimeters wide (roughly the width of a pencil eraser). It’s round or oval, has a smooth surface with a distinct edge, and is often slightly dome-shaped. The color is even: pink, tan, or brown throughout. Most adults have between 10 and 40 common moles, and having them is completely normal.
Atypical moles, sometimes called dysplastic nevi, look a bit different. They tend to be larger than 5 millimeters, with a mixture of colors ranging from pink to dark brown. Their surface is usually flat rather than dome-shaped and may feel slightly scaly or pebbly. The border is irregular and can fade into the surrounding skin rather than having a clean edge. Having atypical moles doesn’t mean you have cancer, but it does mean you should pay closer attention during self-checks.
The ABCDE Rule
The most widely used framework for evaluating moles is the ABCDE rule, developed to describe features of early melanoma. It gives you five specific things to look for:
- Asymmetry: One half of the mole doesn’t match the other. If you drew a line down the center, the two sides would look different in shape or size.
- Border: The edges are ragged, notched, or blurred rather than smooth and well-defined. Pigment may appear to spread into the surrounding skin.
- Color: The mole contains more than one shade. You might see a mix of black, brown, and tan, or patches of white, gray, red, pink, or blue within a single spot.
- Diameter: The mole is larger than 6 millimeters (about the size of a pencil eraser). Melanomas can be smaller, but most exceed this threshold.
- Evolving: The mole has changed in size, shape, color, or feel over the past few weeks or months. Any visible change is worth noting.
A mole doesn’t need to check every box to be concerning. Even one of these features, particularly if the mole is evolving, is reason enough to have a dermatologist take a closer look.
The Ugly Duckling Sign
The ABCDE rule works well for evaluating a single mole, but there’s a complementary approach that looks at patterns across your skin. Your moles tend to resemble one another. They share a general color palette, size range, and shape. The “ugly duckling” sign means spotting the one mole that looks noticeably different from all the others on your body.
This could be a dark mole surrounded by lighter ones, a large mole in an area where all the others are small, or a flat spot among raised ones. Research published in the Journal of the American Academy of Dermatology found this approach is sensitive for melanoma detection because melanoma often stands out from a person’s normal mole pattern. During your self-exam, step back and compare moles in the same area. If one clearly doesn’t belong, flag it.
How to Do a Full-Body Self-Exam
You’ll need a full-length mirror, a hand mirror, and good lighting. The American Academy of Dermatology recommends a systematic approach so you don’t miss any area:
Start by standing in front of the full-length mirror and examining your body from the front, then turn and check from the back. Raise your arms to see your sides clearly. Next, bend your elbows and carefully look at your forearms, underarms, fingernails, and palms. People often skip the hands, but skin cancer can appear there too.
Move to your lower body. Check the backs of your legs and feet, the spaces between your toes, your toenails, and the soles of your feet. Then use the hand mirror to examine the back of your neck and your scalp, parting your hair as you go to get a clear view. Finally, use the hand mirror to check your back and buttocks, areas that are easy to overlook but get significant sun exposure.
The whole process takes about 10 to 15 minutes. Taking photos of moles on your phone can help you track changes over time, giving you a reliable reference point for your next check. Aim to do this once a month so changes don’t go unnoticed for long.
Spots That Aren’t Moles but Still Matter
Not every skin cancer looks like a suspicious mole. Basal cell carcinoma, the most common type of skin cancer, often doesn’t resemble a mole at all. On lighter skin, it can appear as a firm, raised, shiny pink or red bump. On darker skin tones, it tends to look brown, black, or blue. It can also show up as a round area with a sunken center that scabs over and bleeds, a rough scaly patch (especially near the ears), or a spot that looks like a freckle or age spot but feels scaly to the touch.
One of the most telling signs of basal cell carcinoma is a sore that heals and then returns, or simply never heals at all. If you have a spot like this anywhere on your skin, it deserves attention even though it looks nothing like a classic mole.
What Happens if Something Looks Suspicious
When a dermatologist sees a mole that warrants further evaluation, the next step is typically a biopsy, where a small sample of tissue is removed and examined under a microscope. There are a few types, and which one is used depends on what the doctor suspects.
A shave biopsy is the most common. The doctor uses a razor or scalpel to take a thin sample from the top layer of skin, then applies pressure or a topical treatment to stop bleeding. No stitches are needed. A punch biopsy goes deeper, using a small circular tool (about the size of a pencil eraser) to remove a round core of tissue. This may require one or two stitches. If melanoma is suspected, an excisional biopsy is more likely. A surgeon removes the entire lesion with a scalpel and closes the site with stitches, ensuring all the suspicious tissue is captured for testing.
All three are done with local anesthesia, so you’ll feel pressure but not pain. Results typically come back within one to two weeks.
Who Should Check More Carefully
Everyone benefits from regular self-exams, but certain factors put you at higher risk. Having a large number of common moles (50 or more) or having atypical moles increases your melanoma risk. So does a personal or family history of melanoma, a history of severe sunburns, fair skin that burns easily, and frequent use of tanning beds.
If any of these apply to you, monthly self-exams become especially important, and you may benefit from having a dermatologist perform a professional full-body skin exam on a regular schedule. During a professional exam, the dermatologist uses a dermatoscope, a magnifying instrument with a built-in light, to see structures in the skin that aren’t visible to the naked eye. This picks up patterns that even a careful self-exam can miss.