ABCDE Mole Self-Check

Check a mole against the five ABCDE warning signs in about two minutes. Plain language, no sign-up, nothing leaves your phone.

Just want the basics? When to see a dermatologist

What the ABCDE rule means, and where it stops

The ABCDE rule is a memory aid for the warning signs of melanoma, the most serious skin cancer. It's a useful place to start, because it gives you five concrete things to look for instead of a vague "does this look bad?". But it has a real limit worth being honest about: a single glance at a mole can only tell you so much. Here's what each letter means, and why the last one matters most.

A is for Asymmetry

Draw an imaginary line through the middle of the mole. In a typical mole, the two halves roughly match. In a concerning one, the halves look different in shape. On its own, asymmetry is common and harmless in plenty of moles. It's one signal among several, not a verdict.

B is for Border

Typical moles tend to have smooth, even edges. Borders that are ragged, notched, blurred or scalloped are worth noting. That said, many ordinary moles have slightly irregular edges too, which is why no single sign should be read on its own.

C is for Colour

A typical mole is usually one even shade of brown. Several colours in one mole, such as different browns plus black, red, white or blue, is a more notable sign. Even, consistent colour is reassuring. A patchwork is worth a closer look.

D is for Diameter

Melanomas are often larger than about 6 mm across (roughly a pencil eraser) by the time they're noticed, though not always. Plenty of harmless moles are larger than 6 mm, and some early melanomas are smaller. Size is a hint, never a rule.

E is for Evolving, the sign you can't judge in one look

This is the most important letter, and the one a single self-check can't really answer. A mole that's changing in size, shape, colour, or how it feels (itching, bleeding, crusting) is the signal dermatologists weigh most heavily. But "changing" is a comparison across time. You can't see change in a single photo or a single glance in the mirror. You can only see it by comparing the same mole to how it looked weeks or months ago.

That's the honest limit of any one-time self-check, ABCDE included. It's a snapshot, and melanoma reveals itself in the story. The way to actually assess the "E" is to keep a dated baseline photo and compare over time. That's what mole tracking in the Scanoma app is built for, alongside a licensed dermatologist who reviews your case rather than an algorithm.

When to see a dermatologist

You don't need to wait for a "perfect score" on any checklist. See a dermatologist about any spot that's new, changing, growing, bleeding, itching, or simply different from your other moles (the "ugly duckling"). A self-check is a prompt to get a professional opinion, not a substitute for one. When in doubt, get it reviewed.

Track a mole over time, and have a real dermatologist review it

A self-check is only a snapshot. Scanoma lets you keep a dated baseline photo to spot change, and a licensed dermatologist personally reviews every consultation, usually within 12 hours.

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