Signs and symptoms

Melanomas can start with a change to normal skin. This may look like a dark area or an abnormal new mole. You should check your skin regularly and speak to your GP if you notice any changes.

Other melanomas develop in a mole or freckle that you already have. It can be difficult to tell the difference between a melanoma and a normal-looking mole.

The ABCDE list helps you know what to look for:

  • A – Asymmetrical moles – irregular in shape
  • B – Border of a mole – blurred or has jagged edges
  • C – Colour of a mole – if a mole has more than one colour
  • D – Diameter (width) – irregular moles are usually larger than 7mm
  • E – Evolving – melanoma moles often change (evolve).

If you notice any of these signs, or if you have any marks on your skin or a mole that tingles or bleeds, visit your doctor straight away.

Symptoms of melanoma

About half of all melanomas start with a change in previously normal-looking skin. This usually looks like a dark area or an abnormal new mole. Other melanomas develop from a mole or freckle that you already have.

It can be difficult to tell the difference between a melanoma and a normal mole. The following checklist (known as the ABCDE list) will give you an idea of what to look out for:

A – Asymmetry

Most melanomas are likely to be irregular or asymmetrical. Ordinary moles are usually symmetrical (both halves look the same).

Photographs showing melanoma symptom A - asymmetry
Photographs showing melanoma symptom A - asymmetry

The left photograph shows a melanoma with an asymmetrical shape. The right photograph shows a normal mole with no asymmetry.

B – Border

Melanomas are more likely to have an irregular border with jagged edges. Ordinary moles usually have a well-defined, regular border.

Photographs showing melanoma symptom B - border.
Photographs showing melanoma symptom B - border.

The left photograph shows a melanoma with an irregular border. The right photograph shows a normal mole with a clear border.

C – Colour

Melanomas tend to be more than one colour. They may have different shades, such as brown mixed with a black, red, pink, white or bluish tint. Normal moles tend to be one shade of brown.

Photographs showing melanoma symptom C - colour.
Photographs showing melanoma symptom C - colour.

The left photograph shows a melanoma with colour difference. The right photograph shows a normal mole with no colour difference.

D – Diameter (width)

Melanomas are usually more than 7mm in diameter. Moles are normally no bigger than the blunt end of a pencil (about 6mm across).

Photographs showing melanoma symptom D - diameter.
Photographs showing melanoma symptom D - diameter.

The left photograph shows a melanoma with diameter change. The right photograph shows a normal mole with no change in diameter.

E – Evolving (changing)

Look for changes in the size, shape or colour of a mole. The change in shape can include the area becoming raised or dome-shaped.


When to see a doctor

Visit your doctor straight away if you have:

  • any of the ABCDE signs
  • any unusual marks on the skin that last for more than a few weeks
  • a mole that tingles or itches
  • crusting or bleeding of a mole
  • something growing under a nail or a new dark-coloured stripe along part of the nail.

A good time to check your skin is after a bath or shower. Make sure you have plenty of light. Use a full-length mirror and a small hand-held mirror for areas that are hard to see. This will get easier with time, as you become more familiar with your skin and what your moles normally look like.

You can ask your partner, a relative or friend to look at your back, neck and parts of your skin that are hard to see. You could also take pictures of your moles so you can see if there are any changes over time. Checking for these signs is very important as melanoma can usually be cured if it’s found at an early stage.