The Different Types of Moles — and Which Ones Matter

Most adults have between 10 and 40 moles. The vast majority are entirely harmless — but knowing which ones to watch saves lives. This guide walks through the main mole types our physicians see every day, with simple language and no scare tactics.

Round or oval, smaller than a pencil eraser (6 mm), one even colour — typically tan, brown or pink. They appear in childhood and adolescence and usually stay stable for life.

If a common mole hasn't changed in years, it almost never needs treatment unless it bothers you cosmetically or catches on clothing.

Larger than common moles, with irregular borders and uneven colour. They are not cancer, but people with several atypical moles have a higher lifetime risk of melanoma and should be examined by a physician annually.

A — Asymmetry: one half doesn't match the other.

B — Border: edges are jagged, blurred or notched.

C — Colour: more than one shade, especially black, red or white.

D — Diameter: larger than 6 mm (about a pencil eraser).

E — Evolving: the mole is changing in size, shape, colour, or starts to itch or bleed.

Any single feature is worth a check. Two or more, especially the E, should be seen promptly.

Every concerning lesion is examined with a dermatoscope — a magnifier that lets the physician see pigment patterns invisible to the naked eye. If a biopsy is needed, it's done the same day in most cases, with results discussed in plain language.