Checking Your Skin: Which Mole Changes Matter

The change is what matters, not the mole. A spot that is growing, shifting color or shape, bleeding, itching or refusing to heal should be looked at by a doctor, even if it seems unremarkable, and a stable mole you have had since childhood almost never needs anything.

Most people have between ten and forty moles. Learning your own pattern is more useful than memorising a checklist.

The two rules worth knowing#

ABCDE is the standard framework for pigmented lesions:

• Asymmetry. One half does not match the other
• Border: ragged, notched or blurred edges
• Colour: more than one color, or uneven distribution
• Diameter. Larger than about 6 mm, though small melanomas exist
• Evolving: any change over weeks to months

The ugly duckling sign is arguably more useful in practice. Your moles tend to resemble each other. The one that clearly does not belong in the family deserves attention, even if it passes every ABCDE criterion.

Not every skin cancer is a mole#

Melanoma gets the attention, but basal cell and squamous cell carcinomas are far more common. They look different: a pearly or waxy bump, a flat scaly patch, a persistent sore that scabs and reopens, or a firm growing nodule. A sore that has not healed in four weeks is worth showing someone.

Actinic keratoses, rough, scaly patches on sun-exposed skin in older adults, are pre-cancerous rather than cancerous, and treatable.

Who is at higher risk#

Fair skin that burns easily, red or blond hair, many moles or several atypical ones, a history of blistering sunburn especially in childhood, use of sunbeds, previous skin cancer, a first-degree relative with melanoma, and immunosuppression after transplant or from medication.

Outdoor work is a genuine and under-recognized risk factor. In construction, agriculture, fishing and any role with hours of daily sun, cumulative ultraviolet exposure is an occupational hazard in the same sense as noise or dust, and shade, timing, clothing and sunscreen belong in the risk assessment rather than being left to personal choice.

How to check yourself properly#

Once a month, in good light, after a shower. Work through a fixed order so nothing gets skipped: face and ears, scalp with fingers or a comb, neck, chest and abdomen, both arms including between fingers and under nails, back and shoulders using a mirror or another person, buttocks, legs, and finally soles and between the toes.

Photograph anything you are unsure about, with a ruler or coin for scale, and re-photograph it a month later from the same distance. That comparison answers the question far better than trying to remember.

Where this fits#

Skin checks belong to the same category as blood pressure and screening tests: small, cheap habits that mostly find nothing and occasionally find something early. The fuller guide to health checkups by age explains what else belongs on that list in each decade.