what are moles?

Have you ever noticed a small brown spot on your skin? Those are moles, and they’re actually quite common in Australia. In fact, with our sunny climate and high UV exposure, many of us Aussies have a fair few scattered across our bodies.

While moles are usually harmless, being familiar with them is important. Understanding what moles are and how to identify any changes can be crucial. This is especially important because Australia also has a high rate of melanoma, a serious form of skin cancer

Early detection is key to successful treatment for melanoma, and that’s where regular mole checks come in. You can take charge of your skin health by keeping an eye on your moles and knowing when to see a doctor.

What are Moles?

Moles, also known medically as nevi, are those small spots you see on your skin. They come in various colours and textures, and chances are you have a few! 

Moles develop when pigment-producing cells in your skin, called melanocytes, grow in clusters instead of being spread out evenly. These melanin-rich clusters are what give moles their characteristic colour.

Different type of moles

There are actually a few different types of moles, each with its own characteristics. Let’s explore the most common ones:

1. Common Moles:

These are the most frequently occurring type of mole. They’re usually:

  • Colour: Light brown, dark brown, black, or even tan.
  • Size: Smaller than 6 millimetres (about the width of a pencil eraser).
  • Shape: Round or oval.
  • Texture: Smooth or slightly raised.

2. Dysplastic Nevi (Atypical Moles):

These moles are less common than common moles, but it’s important to be aware of them. They have some irregular features and may require a doctor’s evaluation. Here’s what to watch for:

  • Colour: Can vary within the same mole, with shades of brown, black, tan, red, or pink.
  • Size: Can be larger than common moles, sometimes exceeding 6 millimetres.
  • Shape: May be irregular, with uneven borders.
  • Texture: May be smooth or raised.

3. Congenital Nevi (Birthmarks):

These moles are present at birth and are caused by an even larger cluster of melanocytes developing in the skin before birth. They can be:

  • Colour: Similar to common moles, ranging from brown and black to red, pink, or tan.
  • Size: Can vary greatly, from small to quite large.
  • Shape: Can be irregular in shape.
  • Texture: May be smooth, raised, or even hairy.

4. Blue Nevi:

These less common moles appear blue due to the deeper location of the melanocytes within the skin. They’re typically harmless but can sometimes be mistaken for melanomas. Here are some characteristics:

  • Colour: Deep blue or blue-grey.
  • Size: Usually smaller than 1 centimetre (about the width of your pinky fingernail).
  • Shape: Round or oval.
  • Texture: Smooth and firm.

These are just some general descriptions. Mole variations exist, so it’s always best to consult a mole clinic for any concerns.

Signs and Symptoms of Moles

While moles come in a variety of appearances, most share some common characteristics. Knowing these typical signs can help you become familiar with your own moles and identify any potential changes.

  • Colour: Moles can range in colour from light brown to dark brown, black, tan, and even pink or red. A single mole may be uniform in colour or have a combination of shades.
  • Size: Most moles are smaller, typically less than 6 millimetres in diameter—about the width of a pencil eraser.
  • Shape: Moles are generally round or oval in shape. However, it’s important to note that some moles, particularly congenital nevi (birthmarks), can have irregular borders.
  • Texture: Moles’ textures can vary slightly. They may be smooth to the touch or slightly raised. Some moles may even have hairs growing out of them.

Now, let’s discuss a crucial tool for mole checks: the ABCDE rule. This simple acronym helps you remember the key warning signs to watch out for:

  • A – Asymmetry:  Imagine dividing your mole in half. If the two halves don’t match in size or shape, that’s a cause for concern.
  • B – Border irregularity:  The border of a healthy mole should be smooth and well-defined. Look out for moles with ragged, blurred, or notched edges.
  • C – Color variation:  A uniform colour is typical for most moles. Be wary of moles with a mix of colours, such as brown, black, red, white, or blue, all within the same spot.
  • D – Diameter greater than 6mm:  As mentioned earlier, most moles are smaller than a pencil eraser. If you have a mole larger than 6 millimetres in diameter, it’s best to get it checked by a doctor.
  • E – Evolution (changes):  Moles can stay the same for years. However, any changes in a mole’s size, shape, colour, or any new symptoms like itching, bleeding, or crusting warrant a doctor’s visit.

The ABCDE rule is a guide, not a definitive diagnosis tool. If you have any concerns about a mole, it’s always best to err on the side of caution and consult a doctor or dermatologist.

Causes and Risk Factors of Moles

The exact reasons why some people develop more moles than others remain a bit of a mystery. However, researchers have identified several factors that can influence mole formation:

  • Genetics: If your family has a history of moles or melanoma, you may be more likely to have a higher number of moles yourself.
  • Fair Skin: People with lighter skin tones naturally produce less melanin, the pigment that gives skin its colour. This makes them more susceptible to sun damage, which can trigger mole development.
  • Sun Exposure: Ultraviolet (UV) radiation from the sun is a major risk factor for moles. Intense or frequent sunburns, especially during childhood, can increase the number of moles you develop.
  • Large Number of Moles: Having more than 50 moles is considered a risk factor for melanoma. This highlights the importance of monitoring your moles and being extra vigilant if you have a high mole count.

While these are some established risk factors, it’s important to remember that moles can develop on anyone, regardless of skin tone or sun exposure habits. 

When to See a Doctor About a Mole

Knowing when to see a doctor about a mole is vital for early detection and treatment of any potential issues. While the ABCDE rule provides a helpful framework, it’s not the only sign to watch for. Here’s when seeking professional advice is crucial:

  • Changes according to the ABCDE rule: As discussed earlier, any changes in a mole’s Asymmetry, Border, Color, Diameter (greater than 6mm), or Evolution (changes in size, shape, or colour) warrant a doctor’s visit.
  • Bleeding: A mole that bleeds for no apparent reason is a cause for concern.
  • Itching: Itchy moles can be a sign of irritation or inflammation, but they can also be a warning sign of something more serious.
  • Crusting or oozing: If a mole develops a crust or starts oozing pus, it’s important to have it checked by a mole clinic for any underlying issues.

Might be interested: Can moles be cancerous?

Sun Safety Tips for Reducing Mole Risk

Living in Australia means lots of sunshine but also a high UV index. Sun protection is crucial to reduce your risk of moles and melanoma. Here are some sun safety tips:

  • Seek shade during peak sun hours: The sun’s rays are strongest between 10 am and 4 pm. Plan your outdoor activities for these times, or find some shade to relax in. Parks with plenty of trees or shade structures are perfect options.
  • Slip, Slop, Slap, Seek, Slide: This catchy Aussie sun safety slogan perfectly summarizes the key steps: Slip on sun-protective clothing, Slop on broad-spectrum SPF 30+ sunscreen generously, Slap on a hat, Seek shade during peak sun hours, and Slide on sunglasses with good UV protection.
  • Sun-protective clothing: Cover up with loose-fitting clothing made from tightly woven fabrics like cotton or linen. Opt for long sleeves, pants, and a wide-brimmed hat for maximum protection.
  • Sunscreen: Apply a broad-spectrum SPF 30+ sunscreen generously to all exposed skin at least 20 minutes before going outside. Don’t forget areas like your ears, neck, and the tops of your feet. Reapply sunscreen every two hours or more often if you’re sweating or swimming.


Moles are a common occurrence, but understanding them and being aware of any changes is crucial for your skin health. Remember the ABCDE rule for mole checks, and don’t hesitate to see a doctor if you have any concerns.

Consider visiting the Capstone Medical Centre in Southbank, Australia, for mole checks and consultations with qualified professionals. We offer a range of skin cancer services, including mole mapping and full-body skin checks. 


  • www.cancer.org.au/cancer-information/causes-and-prevention/moles
  • www.aafp.org/pubs/afp/issues/2000/0715/p357.html
  • moles-melanoma-tool.cancer.gov/What-are-moles-dysplastic-nevi,be-raised-from-the-skin
  • www.beaumont.org/conditions/skin-moles
  • www.melanomascan.com.au/News/maintaining-healthy-skin-sun-safety-tips-and-best-practices.html