Skin health guide
The ABCDE rule for moles
The ABCDE rule is the standard checklist GPs and dermatologists use to assess whether a mole needs attention. Understanding it helps you know what to look for — and when to act.
What is the ABCDE rule?
The ABCDE rule is a widely used framework for identifying potential warning signs in moles. It stands for Asymmetry, Border, Colour, Diameter, and Evolving. Each letter points to a characteristic that, if unusual, may warrant a closer look from your GP or dermatologist.
No single ABCDE feature is diagnostic on its own — it's the combination and context that matters. This is why regular monitoring over time is so important.
A — Asymmetry
A healthy mole is typically symmetrical — if you drew a line through the middle, both halves would look similar. An asymmetrical mole, where one half doesn't match the other in shape or size, is worth monitoring closely.
B — Border
Look at the edges of the mole. Smooth, well-defined borders are generally a good sign. Borders that are irregular, ragged, notched, or blurred — especially if they seem to fade into surrounding skin — are worth noting.
C — Colour
Most benign moles are a single, uniform shade of brown. Multiple colours within the same mole — shades of brown, black, red, white, or blue — or uneven colour distribution can be a signal to watch. Colour changes over time are particularly important.
D — Diameter
Melanomas are often larger than 6mm in diameter — roughly the size of a pencil eraser — when first detected. That said, size alone isn't a reliable indicator; small moles can still be problematic, and large moles are not automatically a concern. Growth over time matters more than any single measurement.
E — Evolving
This is often considered the most important factor. Any mole that is changing — in size, shape, colour, elevation, or sensation (itching, bleeding, crusting) — should be seen by a GP. A mole that looks perfectly normal by every other measure but is actively changing deserves prompt attention.
When to see a GP
You don't need to tick every box on the ABCDE checklist to see your GP. Any mole that concerns you — whether it looks different from your others, has changed recently, or simply doesn't feel right — is worth getting checked. GPs would always rather reassure you than miss something.
In Australia, where 2 in 3 people will be diagnosed with skin cancer in their lifetime, a proactive approach to mole monitoring is simply good habit. Early detection remains the single most effective way to improve outcomes.
How MoleWatch uses the ABCDE framework
MoleWatch's AI analysis is built around the ABCDE framework. When you photograph a mole, the app generates a plain-English summary of what it observes — noting asymmetry, border irregularity, colour variation, and size — so you have a consistent reference point for each check.
Crucially, MoleWatch also tracks change over time. The side-by-side comparison feature lets you drag a slider to compare any two photos directly, so you can see exactly what — if anything — has shifted since your last check. That evolving factor, the E in ABCDE, is where MoleWatch is most useful.
MoleWatch is not a diagnostic tool and cannot tell you whether a mole is benign or malignant. It is a tracking tool designed to help you build a consistent routine and bring useful, documented information to your GP when needed.
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