Mr. Onur Gilleard
Qualifications & Experience
Mr Onur Gilleard is a distinguished consultant plastic surgeon on the GMC specialist register. He previously held an NHS consultant post at St Bartholomew’s Hospital in London, specialising in skin cancer and microsurgical reconstruction. In 2021, Mr Gilleard transitioned from the NHS to dedicate himself fully to private practice, allowing him to focus exclusively on providing personalised, high-quality care to his patients. He is recognised as an expert in laser treatments, having conducted research and developed advanced treatment protocols using cutting-edge laser technology to optimise both clinical outcomes and cosmetic results.
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Moles (melanocytic naevi) are clusters of pigment-producing cells. Most form in childhood and early adulthood, driven by genetics and sun exposure, and the great majority are completely harmless. The two facts worth remembering are these: a mole you have had unchanged for years is rarely a worry, and a mole that is new in adulthood or visibly changing is the one to get checked. This guide explains why moles appear, when they matter, and what to do if one concerns you.
Why Moles Form
Moles develop when melanocytes — the cells that produce skin pigment — grow in clusters rather than spreading evenly through the skin. Two main factors drive this: genetics (the number of moles you develop tends to run in families) and ultraviolet exposure, which stimulates melanocytes and is why sun and sunbed exposure, especially sunburn in childhood, increases mole count. Hormonal changes in puberty and pregnancy can also make existing moles darken or new ones appear.
Common Types of Mole
- Congenital naevi — present from birth; larger ones warrant monitoring.
- Common acquired naevi — the everyday moles most of us develop through childhood and youth.
- Atypical (dysplastic) naevi — larger or irregular moles that are usually benign but slightly raise melanoma risk and deserve monitoring; see what to do about atypical moles.
- Halo naevi — moles with a pale ring, where the immune system is reacting; see when a halo naevus is a concern.
Are Moles Dangerous?
The overwhelming majority of moles are harmless and stay that way for life. A small minority can develop into, or mimic, melanoma — the most serious skin cancer. The risk is not in having moles but in failing to notice when one changes. Having many moles, or several atypical ones, modestly raises your overall risk and is a good reason for structured monitoring such as mole mapping.
When to Be Concerned
The reliable framework is the ABCDE rule — assess any mole for:
- Asymmetry, Border irregularity, uneven Colour, Diameter over ~6 mm, and especially Evolving change.
Also note any mole that itches, bleeds, crusts or will not heal, or one that simply looks different from your others (the “ugly duckling”). Our cornerstone guide, how to spot a suspicious mole before melanoma, covers each sign in detail.
What to Do Next
If a mole meets any of those criteria, have it assessed — a clinician can examine it with a dermatoscope and, if needed, remove it for laboratory analysis. If you simply dislike a clearly benign mole, removal is straightforward; the options are explained in our mole removal guide.
Frequently Asked Questions
- Is it normal to get new moles as an adult?
- A few new moles can appear into your 30s and 40s, often from sun exposure, and most are harmless. However, a genuinely new mole in adulthood deserves a closer look, because new lesions are also how melanoma can present. If in doubt, have it checked.
- Does having lots of moles mean I’ll get skin cancer?
- No, but having many moles (roughly 50 or more) or several atypical ones modestly raises your melanoma risk. It is a reason for sun-smart habits and regular monitoring, not for alarm — most people with many moles never develop skin cancer.
- Why has one of my moles changed?
- Moles can darken or grow with hormonal changes, sun exposure or simply age, and most changes are benign. But because change is also the key warning sign for melanoma, any mole that is noticeably evolving should be assessed by a clinician.
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