Skin cancer is the most commonly diagnosed cancer in the UK, and rates have been rising steadily for decades. The encouraging news is that when detected early, the vast majority of skin cancers are entirely treatable. Knowing what to look for — and when to seek professional assessment — is genuinely life-saving knowledge.

Understanding UV damage and why it matters

The relationship between ultraviolet (UV) radiation and skin cancer has been established for decades. UV radiation — from sunlight and from artificial sources such as sunbeds — damages the DNA in skin cells. Over time, this cumulative damage can trigger the abnormal cell growth that leads to skin cancer.

Three types of UV radiation reach the Earth's surface: UVA, which penetrates deeply into the skin and contributes to ageing and cancer risk; UVB, which is the primary cause of sunburn and is closely linked to melanoma; and UVC, which is largely absorbed by the atmosphere and does not reach us. Both UVA and UVB are present year-round in the UK, even on overcast days.

Sunburn — particularly in childhood and adolescence — significantly increases lifetime melanoma risk. But chronic, unprotected sun exposure without burning also accumulates risk over decades. Sun safety is not only relevant on the beach in summer; it is a year-round consideration.

The main types of skin cancer

Not all skin cancers are the same, and understanding the differences is useful when assessing your own skin:

Basal cell carcinoma (BCC). The most common skin cancer, accounting for roughly 75% of all cases. BCCs grow slowly and very rarely spread to other parts of the body. They often appear as a pearly or translucent bump, a flat flesh-coloured patch, or a pink growth with raised edges. They are largely curable when detected early.
Squamous cell carcinoma (SCC). The second most common type, typically appearing as a firm, red nodule or flat lesion with a scaly surface. SCCs can occasionally spread if left untreated, so timely assessment matters.
Melanoma. Less common but the most serious type of skin cancer. Melanoma develops in the cells that give skin its colour (melanocytes) and has a greater tendency to spread if not caught early. It often — though not always — arises from or resembles a mole.

There are also rarer types, including Merkel cell carcinoma and dermatofibrosarcoma protuberans, but the three above account for the vast majority of cases seen in clinical practice.

How to check your skin at home: the ABCDE guide

Regular self-examination is the most accessible form of skin surveillance. The ABCDE framework was developed to help people identify changes in moles that may warrant further attention:

A — Asymmetry. Most benign moles are broadly symmetrical. If one half of a mole looks noticeably different from the other, that asymmetry is worth noting.
B — Border. Benign moles tend to have smooth, clearly defined edges. Irregular, ragged, notched, or blurred borders are more concerning.
C — Colour. A mole that is a single, uniform shade of brown is generally reassuring. Multiple shades — tan, brown, black, red, white, or blue — within the same lesion warrant attention.
D — Diameter. Lesions larger than 6mm (roughly the size of a pencil eraser) are more likely to be significant, though melanomas can be smaller.
E — Evolution. Any mole that is changing — in size, shape, colour, or texture — or any new lesion that appears after the age of 30 deserves professional assessment.

A useful addition to the ABCDE framework is the "ugly duckling" sign: any mole or lesion that looks distinctly different from the others on your body — the one that doesn't fit the pattern — should be looked at by a clinician.

It is also worth being alert to lesions that bleed without injury, itch persistently, or fail to heal over several weeks — these are not features of ABCDE but are clinically significant in their own right.

Who is at higher risk?

While skin cancer can affect anyone, certain factors increase an individual's risk:

Fair skin, light hair, and light eyes. Lower levels of melanin provide less natural protection against UV damage.
A history of sunburn, particularly blistering sunburn in childhood or adolescence.
A large number of moles (more than 50) or a history of atypical (dysplastic) moles.
A personal or family history of skin cancer.
Previous significant sun exposure, whether occupational or recreational.
Use of sunbeds, particularly before the age of 35.
Immunosuppression, including organ transplant recipients and people on certain immunosuppressant medications.

Higher-risk individuals benefit most from proactive, regular professional skin assessments rather than relying solely on self-examination.

Practical sun protection — what actually works

The evidence on sun protection is clear, and the principles are straightforward:

SPF 30 or higher for everyday use; SPF 50 or higher for extended outdoor exposure. Apply generously — most people apply far less than the tested amount — and reapply every two hours and after swimming or sweating.
Broad-spectrum protection covering both UVA and UVB. In the UK, look for the UVA circle logo or a four-star UVA rating alongside the SPF.
Seek shade between 11am and 3pm in summer, when UV intensity is highest.
Protective clothing — tightly woven fabrics, long sleeves, wide-brimmed hats, and UV-protective sunglasses — provides reliable barrier protection.
Avoid sunbeds. The World Health Organisation classifies sunbeds as Group 1 carcinogens. There is no safe level of sunbed use.

A word on vitamin D: many people worry that sun protection will compromise their vitamin D synthesis. In the UK, vitamin D levels are best maintained through a combination of modest, sensible sun exposure and supplementation during autumn and winter — not by forgoing sun protection during peak UV hours.

When to see a clinician

If you notice any of the ABCDE warning signs, a lesion that bleeds spontaneously, or anything on your skin that simply feels wrong or different, do not wait. Early detection of skin cancer — including melanoma — is the single most important factor in successful treatment.

A same-day GP appointment at AtWell means you do not have to wait weeks to have a concern assessed. Our GPs can evaluate any suspicious lesion, provide dermoscopy where appropriate, and arrange onward referral to a dermatologist or surgeon with speed and clarity.

For individuals with multiple risk factors or a family history of skin cancer, a regular, structured skin check as part of a broader annual health assessment is a sensible approach. Our health screening service can incorporate a skin review alongside other preventive health checks.

"I noticed a mole that had changed and finally decided to get it checked. It turned out to be an early melanoma — caught completely in time. I am so glad I did not put it off."
— AtWell patient

Sun safety, skin checks, and when a mole needs attention