Most moles will never cause trouble — but melanoma can develop in a mole or as a new spot, and early detection makes an enormous difference. A few minutes of self-checking each month, combined with professional skin checks at the right interval, is the most effective protection available.
The ABCDE Rule for Self-Checking
- A — Asymmetry: one half of the spot does not match the other
- B — Border: edges are irregular, ragged, blurred or notched
- C — Colour: uneven colour — several shades of brown, black, or areas of red, white or blue
- D — Diameter: larger than about 6 mm (the size of a pencil eraser) — though smaller melanomas occur
- E — Evolving: any change in size, shape, colour, elevation — or a new spot appearing after about age 30, or a mole that is different from all your others ("ugly duckling")
Also watch for the "ugly duckling" sign — one mole that simply looks different from all of your others. It may be completely innocent, but it is the one most worth showing to a doctor.
How to Do a Self-Check Properly
- Pick a regular day each month — the first of the month is easy to remember
- Use a well-lit room plus a hand mirror and a full-length mirror
- Check front and back, scalp (hairdryer helps), ears, neck, armpits, torso, groin, buttocks, and — importantly — palms, soles, fingernails, toenails and between the toes
- Photograph any mole you are watching, with a ruler or coin for scale, so change can be compared objectively
Who Should Have Regular Professional Checks?
Consider a full-body professional skin check at least once a year if you have any of the following:
- Fair skin, light hair/eyes, or skin that burns easily
- Many moles (over 50) or several large or unusual-looking moles
- A personal or family history of melanoma or other skin cancer
- A history of severe or blistering sunburns, tanning-bed use, or heavy outdoor sun exposure
- Immunosuppression or certain medications
- Age over 40 in Australia — simply by virtue of accumulated UV exposure
What Happens at a Professional Mole Check?
- Full-body examination — head to toe including scalp, palms, soles and nails, in a private, respectful setting
- Dermoscopy — a handheld magnifying device with polarised light lets the doctor see structures invisible to the naked eye, sharply improving accuracy
- Mole mapping — for people with many moles, clinical photography creates a baseline so that change can be detected reliably at future visits
- Biopsy if needed — any genuinely suspicious lesion is sampled for an exact diagnosis under local anaesthetic; most checks find nothing needing more than reassurance
A check usually takes 15–30 minutes and involves no pain. If anything needs treatment, you leave with a clear plan — whether that is simple monitoring, removal of a harmless lesion, or treatment of something that was caught early.
This page provides general educational information only. It is not a diagnosis and does not replace individual medical advice. If you are concerned about a lesion, please book a professional skin assessment.
Related Information & Services
Concerned about a spot or lesion?
Skin Cancer Laser Centre, Drummoyne — opening Monday 2 November 2026. Book a professional skin check with our doctors.
BOOK A SKIN CHECK