“It can be difficult to tell the difference between a non-cancerous mole and a cancerous one, particularly if you have a lot of moles or freckles,” says Dr Desai. “But there are some tell-tale signs you can look out for. The A to G method provides a good basis for identification of potentially troublesome moles.”

A: Asymmetry

Normal moles or freckles are completely symmetrical. If you were to draw a line through a normal spot, you would have two symmetrical halves. In cases of skin cancer, spots don’t look the same on both sides.

B: Border

A mole or spot with blurry and/or jagged edges should be seen by a doctor.

C: Colour

A mole that is more than one hue is suspicious and needs to be evaluated by a doctor. Normal spots are usually one colour. This can include the lightening or darkening of the mole. Melanoma cells usually continue to produce melanin, which accounts for the cancers appearing in mixed shades of tan, brown and black.

D: Diameter

If it is larger than a pencil eraser (about ¼ inch or 6mm), it needs to be examined by a doctor. This includes areas that do not have any other abnormalities (colour, border, asymmetry). But, don’t be fooled by size alone – melanoma can be smaller.

E: Elevation/Evolving

Elevation means the mole is raised above the surface and has an uneven surface. Evolving means changing in size, shape and colour.

F: Firm on palpation

This means if any of your moles change from a softer, spongier consistency to a firm consistency.

G: Growing progressively over one month

A mole should remain a consistent size. If your mole continues to grow over more than a month, speak to your doctor.

How to check your moles, reduce your risk of melanoma and when to see a medical professional