Most adults have somewhere between 10 and 40 moles, and the overwhelming majority are completely harmless. But moles are also where melanoma — the most serious form of skin cancer — tends to show up, so it's worth knowing what a healthy mole looks like and which changes deserve attention. The good news is that you don't need medical training to spot a suspicious mole. Dermatologists use a simple memory aid called the ABCDE rule, and once you know it, you can run the same quick check at home.
What a Normal Mole Looks Like
A typical, benign mole is small (usually under 6 millimeters, about the width of a pencil eraser), evenly colored in a single shade of brown or tan, and roughly round or oval with a smooth, clear border. It looks like its neighbors and stays much the same for years. Moles can be flat or raised, and it's normal to have a mix of both. New moles are common in childhood and young adulthood; after about age 40, genuinely new moles are less common, so a brand-new spot in later life is worth a closer look.
The ABCDE Rule
Each letter flags a warning sign. A mole doesn't need all five to be worth checking — even one can be reason enough.
- A — Asymmetry: If you imagine a line through the middle, the two halves of a healthy mole roughly match. One half looking different from the other is a warning sign.
- B — Border: Harmless moles have smooth, even edges. Ragged, notched, blurred, or scalloped borders are worth noting.
- C — Color: A single even shade is reassuring. Multiple colors in one mole — different browns, plus black, red, white, or blue — deserve attention.
- D — Diameter: Melanomas are often larger than 6 mm, though they can be smaller. Size alone isn't a diagnosis, but a larger spot warrants a closer look.
- E — Evolving: This is the most important letter. Any mole that is changing — in size, shape, color, height, or that starts to itch, bleed, or crust — should be checked by a clinician.
The "Ugly Duckling" Sign
Alongside ABCDE, dermatologists watch for the "ugly duckling." Most of your moles tend to resemble one another. If one mole clearly stands out from the crowd — darker, larger, oddly shaped, or simply different from the rest — that outlier is worth flagging, even if it doesn't tick every ABCDE box.
How to Check Your Own Skin
Aim for a self-check every month or two. Use good lighting and a full-length mirror, and a hand mirror for hard-to-see areas: your back, scalp, between the toes, the soles of your feet, and behind the ears. Taking dated photos of moles you're keeping an eye on makes it far easier to notice slow changes over time. If you have many moles, a family history of melanoma, fair skin that burns easily, or a history of significant sun exposure or sunburns, checking becomes especially worthwhile.
When to See a Doctor
Book an appointment if a mole meets any ABCDE criterion, is the "ugly duckling," or is doing anything new — itching, bleeding, oozing, crusting, or not healing. Don't wait for pain; melanoma is often painless in its early, most treatable stage. A general practitioner can examine it and refer you to a dermatologist for a dermoscopic exam or biopsy if needed. Caught early, melanoma is highly treatable, which is exactly why prompt checking matters.
Running your photo through an AI photo check can give you a quick triage level — from self-care to "see a specialist" — and a plain-language summary to help you decide whether an appointment is worth booking. Treat that as a helpful nudge, not a verdict: a screening tool can point you in the right direction, but only a clinician examining your skin in person can confirm what a mole actually is.
Téléversez une photo pour obtenir gratuitement un niveau de triage en langage clair et une prochaine étape suggérée. Sans compte, sans abonnement.
Vérifier ma photo — gratuitIl s'agit d'informations générales de santé, et non de conseils médicaux personnalisés. Consultez toujours un professionnel de santé agréé au sujet de vos propres symptômes. En cas d'urgence, appelez votre numéro d'urgence local.