Skin cancer is one of the most common forms of cancer in the UK, yet it is also one of the most treatable when detected early. Noticing a change in your skin can be unsettling, but equipping yourself with the right knowledge is the most powerful tool you have for protecting your health.
While the thought of finding a suspicious mole is frightening, it is important to remember that most moles are benign (non-cancerous). However, being able to distinguish between a harmless blemish and a potential melanoma is a vital skill.
Melanoma is a type of skin cancer that can spread to other organs in the body. According to the NHS, typical signs include a new mole or a change in an existing one. It is not just about vanity or skincare; it is about knowing your body.
This article explores the early warning signs of melanoma, breaks down the famous ABCDE rule, and offers practical advice on when to speak with a healthcare professional.
What is melanoma?
Melanoma is a serious form of skin cancer that develops in the cells called melanocytes. These are the cells responsible for producing melanin, the pigment that gives your skin its colour. When these cells begin to grow out of control due to DNA damage—often caused by ultraviolet (UV) radiation—they can form a malignant tumour.
While melanoma is less common than basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), it is considered more dangerous because of its ability to spread (metastasise) more rapidly if left untreated.
Recent data from Cancer Research UK indicates that melanoma skin cancer rates have increased significantly over the last few decades. This rise highlights the importance of regular self-checks and sun safety awareness.
Although it can appear anywhere on the body, it is most commonly found on the backs of men and the legs of women. However, it can also develop in areas not typically exposed to the sun, such as the soles of the feet or palms of the hands.
Understanding the biology of your skin helps you realise why protection is necessary. It is not just about avoiding a sunburn; it is about preventing the cellular damage that triggers these changes.
Identifying the signs: The ABCDE rule
Dermatologists and healthcare providers worldwide use the ABCDE checklist to help patients identify potential melanomas. This simple guide focuses on the physical characteristics of moles that distinguish them from normal skin spots.
If you notice any of the following features, you should prioritise booking an appointment with your GP.
A for Asymmetry
Most benign moles are symmetrical. If you were to draw a line through the middle of a normal mole, the two halves would match.
In contrast, early-stage melanoma is often asymmetrical. One half of the mole or lesion does not match the other. This lack of balance in shape is a primary red flag. When checking your skin, look for spots that appear lopsided or irregular in their general form.
B for Border
Normal moles typically have smooth, defined edges. They look like clear, distinct spots on the skin.
Melanomas often have irregular borders. The edges may look blurred, ragged, or notched. The pigment might appear to spread into the surrounding skin, making it difficult to define exactly where the mole ends and normal skin begins. This “bleeding” of colour or lack of definition is a significant warning sign.
C for Colour
Benign moles are usually a single shade of brown. Homogeneity is a sign of health in a mole.
A warning sign of melanoma is the presence of multiple colours or uneven distribution of colour. You might see shades of tan, brown, and black mixed together. As the melanoma progresses, you may also notice areas of white, grey, red, pink, or even blue.
For a comprehensive guide on different skin cancer types and their visual characteristics, Healthline offers extensive resources to help you visualise these differences.
D for Diameter
Size matters when evaluating skin lesions. While melanomas can be tiny, anything growing larger than 6 millimetres (about the size of a pencil eraser) should be investigated.
However, do not ignore smaller spots if they exhibit other signs from this list. Many melanomas are detected when they are quite small, especially if the person is vigilant about regular skin checks.
E for Evolving
This is perhaps the most critical factor. Any mole that is evolving or changing over time requires attention.
This evolution could be a change in size, shape, or colour. It also includes new symptoms such as itching, tenderness, bleeding, or crusting. If a mole that has been on your body for years suddenly starts to look or feel different, it is a signal that the cells are active and potentially unstable.
Detailed guidance from the British Skin Foundation emphasises that change is the most reliable indicator of malignancy.
The ‘Ugly Duckling’ sign and other warnings
Not all melanomas fit neatly into the ABCDE criteria. Another helpful concept is the “Ugly Duckling” sign.
Most people have a signature type of mole—their moles tend to look similar to one another. An Ugly Duckling is a lesion that stands out because it looks completely different from your other moles. Even if it does not perfectly match the ABCDE rules, if it looks odd compared to its neighbours, it should be checked.
Nodular Melanoma
Some aggressive forms, like nodular melanoma, do not follow the standard rules. They might grow vertically rather than spreading outwards. According to Macmillan Cancer Support, these can present as firm, raised bumps that may be red, pink, or skin-coloured. They often grow quickly and require immediate medical assessment.
Hidden Melanomas
Melanoma can develop in areas that receive little to no sun exposure.
- Acral Lentiginous Melanoma: Appears on the palms, soles of the feet, or under the nails. It is more common in people with darker skin tones.
- Mucosal Melanoma: Develops in mucous membranes, such as the lining of the nose, mouth, or genitals.
- Ocular Melanoma: Occurs in the eye and is often detected during routine eye exams.
Comparison: Normal Moles vs. Potential Melanoma
The following table outlines the key differences to help you distinguish between a standard mole and a lesion that requires professional evaluation.
| Feature | Normal Mole (Benign) | Potential Melanoma (Malignant) |
|---|---|---|
| Symmetry | Symmetrical; halves match. | Asymmetrical; halves do not match. |
| Edges | Smooth, even, and distinct. | Blurred, ragged, or notched. |
| Colour | One uniform colour (usually brown). | Varied colours (black, brown, tan, red). |
| Size | Usually smaller than 6mm. | Often larger than 6mm (but can be smaller). |
| Texture | Smooth and consistent. | Can be scaly, crusty, or bleeding. |
| Sensation | Painless. | May itch, tingle, or feel tender. |
| Evolution | Stays the same over years. | Changes in size, shape, or colour. |
Risk factors and prevention tips
While anyone can get melanoma, certain factors increase your likelihood of developing it. Understanding your risk profile helps you determine how vigilant you need to be.
Key Risk Factors
- Pale Skin: Having skin that burns easily, red or blonde hair, and blue or green eyes increases risk. However, people with dark skin can and do get melanoma, often in less visible areas.
- UV Exposure: A history of severe, blistering sunburns, especially in childhood, significantly raises risk. The World Health Organization (WHO) classifies UV radiation from the sun and tanning beds as a Group 1 carcinogen.
- Moles: Having more than 50 moles, or having atypical moles (dysplastic nevi), puts you at higher risk.
- Family History: If a close relative has had melanoma, your risk is higher.
Actionable Prevention Tips
- Wear High SPF: Use a broad-spectrum sunscreen with at least SPF 30 (preferably SPF 50) every day, even when it is cloudy. The British Association of Dermatologists recommends applying it generously 20 minutes before going outside.
- Seek Shade: The sun is strongest between 11 am and 3 pm. Limit exposure during these hours.
- Protective Clothing: Wear wide-brimmed hats and sunglasses. Tightly woven fabrics offer better protection than loose knits.
- Avoid Sunbeds: Artificial UV rays are intensely damaging. GOV.UK legislation restricts sunbed use for under-18s due to the proven cancer risks, and health experts advise adults to avoid them entirely.
- Regular Self-Exams: Check your skin once a month. Use a mirror for hard-to-see places like your back.
Frequently Asked Questions
Does melanoma always itch or bleed? No. While itching, tenderness, or bleeding can be signs of advanced melanoma or specific types, many early-stage melanomas are painless. Do not wait for pain to seek help. Rely on visual cues like shape and colour changes.
Can a mole turn into cancer if you scratch it? Trauma to a mole, such as scratching or shaving over it, does not cause cancer. However, if a mole bleeds easily with minor friction, that fragility itself could be a sign of cellular changes and should be checked.
Is melanoma hereditary? Genetics play a role. According to NICE guidelines, familial melanoma is relatively rare but significant. If you have two or more close relatives who have had melanoma, you may be eligible for special screening programmes.
Can darker skin get melanoma? Yes. While less common, it is often diagnosed at a later stage in people with darker skin because it is mistaken for other conditions or occurs in hidden areas like the soles of the feet.
The bottom line
Early detection of melanoma saves lives. The difference between a simple removal procedure and a life-threatening illness often comes down to timing.
By memorising the ABCDE rule and keeping an eye out for the “Ugly Duckling” on your skin, you are taking proactive steps to protect your future. Do not rely on self-diagnosis; if you spot something unusual, consult your GP immediately.
Remember, your skin has a memory. The sun exposure you receive today affects your health years down the line. As noted in research published by the Skin Cancer Foundation, daily sun protection is the single most effective way to reduce your risk.
Prioritise your health, check your skin regularly, and never hesitate to ask for a professional opinion.
