Is This Mole Normal? What to Look For, and When to Have It Checked

Reviewed by Dr Eugene Lim | MBBS, Dr Cindy’s Medical Aesthetics, Singapore. Fully registered with the Singapore Medical Council, practising alongside Dr Cindy Yang.

A normal mole is usually symmetrical, fairly even in colour, smooth or clearly edged, and stable over time. Most adults have multiple moles, and most acquired moles appear during childhood, adolescence and early adulthood.

A mole needs a doctor’s examination when it changes in size, shape or colour, when it looks different from your other moles, when it bleeds or itches without an obvious explanation, or when a new pigmented lesion appears later in adult life.

Change carries particular weight. A mole that has looked the same for years is generally more reassuring than one that has done something new over the past few months. But stability alone does not prove that a lesion is benign, just as one unusual feature alone does not prove that it is melanoma.

Most people asking this question have just noticed something. A mole on the shoulder that looks darker in the mirror after a weekend at the beach. A spot on a child’s arm that was absent from last year’s photographs. A brown mark on the sole that has never been examined because nobody looks there.

The difficulty is that much of the familiar skin-cancer advice comes from predominantly fair-skinned populations, where UV-related melanoma patterns receive most of the attention. In Asian populations, acral melanoma — involving the palms, soles and nail units — accounts for a larger proportion of melanoma than it does in fair-skinned populations. That difference matters when deciding where to look.

The checklists are still worth learning, provided you know where they fall short.

This article sets out what normal looks like, the two checks doctors use, where melanoma can appear on Asian skin, why moles change, and when to have one examined. How a mole is removed once it has been assessed is covered separately in our guide to mole removal methods.

What a normal mole looks like, and how many is normal

A mole, or naevus, is a benign proliferation of melanocytes, the pigment-producing cells in the skin. Depending on where those cells sit within the skin, a mole may be flat or raised and may range from skin-coloured to tan, brown or darker.

Most adults have multiple moles. Acquired moles typically appear through childhood and adolescence and into early adulthood, while congenital moles are present at birth or become apparent shortly afterwards.

There is considerable normal variation, so the features below are guides rather than a test that can diagnose a mole from appearance alone.

A normal mole is often symmetrical. If you drew a line through the middle, the two halves would broadly resemble each other.

Its colour is usually fairly even. A benign mole may be tan, brown, dark brown or another consistent colour, depending on the person and the type of mole.

Its edge is usually regular and defined. Many common moles are round or oval and have a reasonably clear boundary with the surrounding skin.

Many common moles are small. The familiar 6 mm figure belongs to the ABCDE warning rule, but it is not a dividing line between benign and malignant. Benign moles can be larger than 6 mm and melanomas can be smaller.

It is usually stable. Long-term stability is reassuring. A new or evolving lesion deserves more attention.

Some benign moles do not fit the textbook picture. Atypical or dysplastic naevi can be larger, irregular in outline and variable in colour. They are not melanoma, although people with numerous atypical naevi can have a higher melanoma risk and may be advised to have periodic skin examinations.

Halo naevi, where a pale ring develops around a mole, are another recognised pattern and are particularly common in children and young adults. They often fade gradually. A new halo around an unusual or changing lesion in an adult, however, still deserves assessment rather than being diagnosed from appearance alone.

Several things patients bring in as moles are something else. Flat brown marks appearing on sun-exposed skin with age may be solar lentigines, discussed in our guide to pigmentation. Waxy or stuck-on brown growths that become more common with age may be seborrhoeic keratoses. Soft, flesh-coloured growths on a stalk around the neck and skin folds may be skin tags.

Telling small skin growths apart covers the commonly confused possibilities in more detail.

The two checks doctors actually use

The ABCDE rule

The ABCDE rule is a useful screening tool for features that should make a pigmented lesion worth examining more closely. It is not a diagnostic test, and a melanoma does not have to satisfy every letter.

A, asymmetry. One half does not resemble the other.

B, border. The edge is irregular, notched, scalloped or poorly defined.

C, colour. Colour varies from one area to another, particularly when a lesion contains several shades or develops areas of black, blue, red, white or grey.

D, diameter. A diameter greater than 6 mm deserves attention, but the number is not a cutoff. Melanomas can be smaller than 6 mm.

E, evolving. A lesion is changing in size, shape, colour, surface or symptoms, or looks noticeably different from before.

Evolving is particularly useful because a benign mole can be larger than 6 mm and remain unchanged for years, while an early melanoma can be smaller than 6 mm.

Change does not automatically mean cancer, and absence of obvious change does not guarantee that a lesion is benign. The point of ABCDE is to identify lesions that deserve proper examination.

The rule also has known limits. Nodular melanoma, for example, may not display the classic ABCD pattern. A new lesion that is elevated, firm and growing deserves prompt assessment even if it is symmetrical and fairly uniform in colour.

The ugly duckling sign

The second check uses the fact that an individual’s moles often share a general pattern.

You may tend to have small dark moles, larger tan ones, predominantly flat moles, or a mixture that still looks recognisably like your own pattern. A lesion that looks distinctly unlike the others is the “ugly duckling.”

The sign needs no ruler. You compare the lesion with the rest of your moles and ask whether one stands out.

It complements ABCDE rather than replacing it. ABCDE asks what is unusual about the individual lesion. The ugly duckling sign asks whether it is unusual for you.

Where melanoma appears on Asian skin, and why the usual advice can miss it

UV exposure is an important risk factor for several forms of melanoma, particularly in fair-skinned populations, and melanomas can occur on areas such as the back, trunk and legs.

But that is not the whole picture.

In Asian populations, acral lentiginous melanoma accounts for a greater proportion of melanoma cases than it does in fair-skinned populations. Acral melanoma occurs on the palms, soles and nail units and is not associated with UV exposure in the same way as the major sun-related melanoma subtypes.

That makes the feet, palms and nails particularly important places to include when checking the skin.

On the sole or palm, a new or changing brown or black patch, particularly one with irregular borders or varying colour, deserves examination. Benign acral moles are common as well, which is why appearance alone is not enough to diagnose one.

Under a nail, longitudinal pigmentation can have many benign causes, particularly in people with more deeply pigmented skin. Features that deserve assessment include a new band affecting a single nail, progressive widening or darkening, irregular colour or borders, nail changes, or pigment extending onto the surrounding nail-fold skin.

A dark nail band is not automatically melanoma, and trauma is not the only benign explanation. The important point is that a new or changing unexplained band should not simply be assumed to be a bruise.

Melanoma remains uncommon in Singapore. Singapore Cancer Registry analyses have consistently found much lower melanoma incidence than is seen in predominantly fair-skinned Western populations. That is reassuring at the population level but does not make an individual suspicious lesion safe to ignore.

Basal cell carcinoma is considerably more common locally than melanoma, followed by squamous cell carcinoma. Basal cell carcinoma frequently develops on sun-exposed skin, particularly the head and neck. It may appear as a pearly or translucent bump, a pigmented lesion, or a sore that repeatedly crusts, bleeds and fails to heal properly.

In more deeply pigmented skin, basal cell carcinomas may themselves contain pigment and can therefore be mistaken for moles. A new or changing lesion on the face that repeatedly bleeds, crusts or fails to heal belongs with a doctor rather than a cosmetic diagnosis made at home.

Why moles appear, change or multiply

Genetics influences the count. The tendency to develop many melanocytic naevi has a genetic component, and having a high number of common or atypical naevi is associated with increased melanoma risk.

That does not mean the moles themselves are waiting to become melanoma. Most melanomas arise de novo rather than from a pre-existing mole. A high mole count is better understood as a marker of increased risk and a reason to pay closer attention to the skin.

Sun exposure contributes. UV exposure, particularly during childhood, is associated with the development of acquired melanocytic naevi and contributes to skin-cancer risk later in life.

Pregnancy deserves more careful wording. It is commonly said that pregnancy normally makes moles enlarge and darken. The evidence is less straightforward.

Moles on areas such as the breasts and abdomen can appear larger as the skin stretches, and subtle dermoscopic changes have been described during pregnancy. But pregnancy should not be used as an explanation for a suspiciously changing mole. A lesion that would concern a doctor outside pregnancy deserves the same assessment during pregnancy.

New lesions become less common with age. Most acquired moles develop earlier in life, so a genuinely new pigmented lesion later in adulthood deserves more attention than another similar mole appearing during adolescence.

That does not mean every new brown spot after 30 is melanoma. Solar lentigines, seborrhoeic keratoses and other benign lesions become increasingly common with age. It means a new lesion should be identified rather than automatically labelled a mole.

Moles can fade with age. The number of melanocytic naevi generally declines later in life, and individual benign moles may gradually become lighter or less prominent. As with darkening, an unusual or rapid change in one lesion should be judged on its own features rather than explained by age alone.

Raised or flat, itchy, bleeding, or growing a hair

Raised moles are often benign. Many benign intradermal naevi are raised, so elevation by itself does not mean melanoma.

What deserves attention is change: a lesion becoming progressively raised, firm or visibly larger, particularly over a relatively short period.

Itching often has ordinary causes. Clothing, friction and irritated surrounding skin can make a mole itch. Persistent itching or tenderness in one lesion, particularly when accompanied by visible change, deserves examination.

Bleeding needs context. A raised mole caught by a razor or scratched accidentally can bleed like any other piece of skin. A lesion that repeatedly bleeds without an obvious injury, ulcerates, crusts or fails to heal deserves assessment.

There are several biological reasons malignant skin lesions can ulcerate and bleed, so there is no need to reduce this to a single mechanism.

A hair does not prove that a mole is benign. Hair can grow through benign melanocytic naevi, but the presence of hair is not a reliable test for malignancy. A hairy mole that develops suspicious changes should be assessed like any other lesion.

Plucking a hair does not turn a mole cancerous, although repeated plucking can irritate the skin. Trimming it is less traumatic.

Colour change needs context. A new area of distinctly different pigmentation within a lesion can be an important warning feature, particularly when accompanied by changes in shape, border or size.

White or grey areas can have several explanations, including regression-related changes, but cannot be interpreted reliably without examining the lesion. They are a reason to look more closely rather than a diagnosis in themselves.

What Singapore adds

Singapore has high year-round UV exposure. There is no winter season in which UV protection becomes irrelevant, and incidental exposure during ordinary daily life adds up over time.

That matters particularly for cumulative sun damage and keratinocyte cancers such as basal cell carcinoma and squamous cell carcinoma.

More deeply pigmented skin provides greater natural protection against UV-related skin damage than very fair skin, which contributes to lower rates of many UV-associated skin cancers. It does not reduce the risk to zero.

Singapore registry data show clear ethnic differences in skin-cancer incidence, with higher overall rates among Chinese Singaporeans than Malay and Indian Singaporeans. These are population-level observations and should not be used to determine whether an individual lesion is benign.

Acral melanoma requires a different way of thinking because UV exposure is not considered its principal driver. Sunscreen therefore does not replace checking the soles, palms and nails.

Singapore’s heat and humidity can also make friction, sweating and irritation around raised skin lesions more noticeable, particularly at the neck, under the arms, around waistbands and in other skin folds.

That makes context useful: a lesion scratched by clothing once is different from one that repeatedly bleeds or changes without an obvious mechanical explanation.

Three things patients commonly get wrong

“I have dark skin, so I do not need to worry about moles.”

More deeply pigmented skin is associated with a lower incidence of many UV-related skin cancers, but melanoma can still occur. Acral melanoma is particularly important in Asian and darker-skinned populations because it occurs on the palms, soles and nail units and may be diagnosed later when these areas are not routinely checked.

Anyone can benefit from knowing what is normal for their skin and noticing a new or changing lesion.

“This mole has been there for twenty years, so it is fine.”

Long-term stability is reassuring, but it does not give a lesion permanent immunity from assessment if something changes.

Most melanomas arise as new lesions, while a minority arise in association with a pre-existing naevus. The practical question is therefore not simply how long the mole has existed. It is whether it has recently changed or developed a suspicious feature.

“I will have it lasered off, and that will check it.”

Laser treatment destroys tissue rather than preserving an intact specimen for histological examination. It therefore cannot provide the pathology information that a biopsy can.

For that reason, a pigmented lesion with suspicious or uncertain features should be medically assessed before cosmetic laser removal is considered.

When tissue diagnosis is required, an appropriate biopsy is performed so that the specimen can be examined under a microscope by a pathologist. The exact biopsy method depends on the lesion, its location and the clinical level of suspicion.

Laser treatment is for lesions that have first been assessed as appropriate for that form of removal. It is not a substitute for diagnosis.

When to have it assessed, and what happens

Check your skin regularly and get to know your own pattern. Use good lighting and, where practical, a mirror or another person to help examine areas you cannot see easily.

Do not stop at the face, arms and chest. Include the back, scalp, palms, soles, between the toes and the nails.

Photographs can be useful when monitoring a particular lesion because they provide an objective comparison over time. Try to use similar lighting, distance and angle each time rather than relying entirely on memory.

Book an appointment when a lesion is changing or looks suspicious. Reasons include a change in size, shape, colour or surface; a lesion that looks distinctly unlike your others; persistent unexplained itching or tenderness; spontaneous or recurrent bleeding; ulceration or a sore that repeatedly fails to heal; a new or changing unexplained pigmented lesion; or a new or changing dark band in a nail.

People with numerous moles, multiple atypical naevi or a personal or strong family history of melanoma may also need a more individualised surveillance plan.

What the assessment involves. The doctor will ask how long the lesion has been present, what has changed and over what period, whether it has bled or caused symptoms, and about relevant personal and family history.

The lesion is then examined in the context of the surrounding skin and, where appropriate, compared with the patient’s other moles.

Dermoscopy can add useful information by allowing trained clinicians to examine structures and pigment patterns that are difficult to appreciate with the naked eye. Whether dermoscopy is required and who should perform further assessment depends on the individual lesion and the clinic’s diagnostic pathway.

There are several possible outcomes.

The first is that the lesion appears clinically benign. You leave knowing what it is likely to be, whether it needs monitoring, and what change should bring you back. If you want a benign lesion removed for cosmetic reasons, the appropriate method depends on its type, depth and location. The options are discussed in our guide to mole removal in Singapore.

The second is that a lesion has features that require tissue diagnosis. An appropriate biopsy can then preserve tissue for histological examination by a pathologist. Depending on the lesion and clinical circumstances, this may involve complete excision or another appropriate biopsy technique.

The third is referral. A lesion that requires specialist assessment or management may be referred to a dermatologist or an appropriate hospital service.

The important distinction is not whether a mole is flat or raised, large or small, or whether you have light or dark skin. It is whether the lesion is behaving like the rest of your skin — and whether there is enough uncertainty that looking at it properly is safer than guessing.

Where to be seen, and who sees you

Dr Cindy’s Medical Aesthetics assesses and removes moles at both of its clinics.

Orchard. 360 Orchard Road, #05-06 International Building, Singapore 238869. Monday and Thursday 11.30am to 7pm, Tuesday, Wednesday and Friday 10am to 8pm, Saturday 10am to 3pm. Closed Sunday and public holidays.

Tampines. 1 Tampines Central 5, #07-01 CPF Tampines Building, Singapore 529508. Monday to Friday 11.30am to 9pm, Saturday 10am to 7pm. Closed Sunday and public holidays.

Assessments are carried out by the clinic’s doctors: Dr Cindy Yang, founder and medical director; Dr Eugene Lim, fully registered with the Singapore Medical Council; and Dr Grace Su, a general practitioner working in aesthetic and lifestyle medicine.

The clinic is a medically led aesthetic practice. Its role with a mole is to examine it, to remove it where removal is appropriate, and to make sure that any lesion removed for a suspicious feature is examined by a pathologist. Presentations that belong with a dermatologist or a hospital skin clinic include any mole with features strongly suggestive of melanoma or another skin cancer, a lesion that has already been biopsied as atypical, a personal or family history of melanoma, a large number of atypical moles needing ongoing surveillance, and a rapidly changing lesion in a child.

Whichever clinic you attend, look for the same five things: a doctor registered with the Singapore Medical Council; an examination of the lesion itself, usually with a dermatoscope; a removal method chosen for the type of mole, and never the other way round; tissue sent for histology whenever a lesion is removed because of any suspicious feature; and a plain statement of the expected mark and healing time before anything is done.

Dr Cindy’s Medical Aesthetics examines a mole before deciding what, if anything, should be done about it.

Frequently asked questions

Is this mole normal?

A normal mole is symmetrical, one or two even shades of brown, smooth and clearly edged, under 6 mm across, and unchanged for years. Most adults have between 10 and 50, nearly all of which appeared before the age of 30. A mole deserves a doctor’s examination when it changes in size, shape or colour, looks different from your other moles, bleeds or itches without injury, or is new after 30. Change is the sign that carries the most weight.

How do I tell if a mole is cancerous?

You cannot tell by looking alone, and neither can a doctor without examining it. What you can do is spot the features that warrant one: asymmetry, an irregular or blurred border, more than two colours, a diameter above 6 mm, and above all change over weeks to months. A firm lesion that is growing is examined whatever its colour. A doctor confirms or excludes cancer by examining the mole and, where needed, by referring it so that it can be removed intact and the tissue sent for histological examination.

What does the ABCDE rule for moles mean?

ABCDE is a checklist for a single mole. A is asymmetry, where one half does not match the other. B is border, an edge that is irregular, notched or blurred. C is colour, more than two shades or a new area of black, blue, red, white or grey. D is diameter above 6 mm. E is evolving, any change in size, shape, colour, surface or symptoms. E was added in 2004 and carries the most weight, because a melanoma may pass the first four tests early on and still change.

What is the ugly duckling sign for moles?

A person’s moles tend to resemble one another, and a melanoma rarely follows that personal pattern. The ugly duckling sign, described in 1998, asks you to compare each mole with its neighbours and pick out the one that looks different from all the rest, whether larger, darker, redder or a different shape. It needs no measuring and no memory of how the mole looked last year, and it catches the mole that has always been different, which the ABCDE rule can miss.

When should I get a mole checked by a doctor?

Book an appointment when a mole has changed in size, shape or colour over weeks to months, looks different from your other moles, itches persistently, is tender, bleeds without injury, or has a crust unhealed after three weeks. A new pigmented spot after 30, a dark band on a single nail, or a facial sore that bleeds, crusts and returns should also be examined. People with more than 50 moles, several atypical moles, or a personal or family history of melanoma are advised to have periodic full-skin examinations.

Is a mole that is itchy or bleeding dangerous?

It depends on the cause. A mole caught by a razor, a fingernail or a strap will bleed, scab and heal within one to two weeks, and intermittent itch in a mole that is rubbed by clothing in Singapore’s humidity is common. Bleeding without any injury, a crust that has not healed within three weeks, repeated bleeding, or persistent itch or tenderness in one mole with no friction to explain it are features that call for a doctor’s examination, because they can mean the lesion is changing from within.

Where does melanoma usually appear on Asian skin?

In East and Southeast Asian skin, melanomas arise far more often on skin that rarely sees the sun: the soles, the palms, and under the nails. These acral melanomas are unrelated to sun exposure. On the sole or palm the sign is a new, irregular or multicoloured patch. Under a nail it is a new, widening or irregular dark band on a single digit, usually a thumb or big toe. Melanoma is uncommon in Singapore, about 6 per cent of skin cancers, which is one reason it is found late.

What causes moles to suddenly appear?

New moles are driven by genetics, sun exposure and hormones. Most appear through childhood and adolescence and into the twenties, and puberty, pregnancy and hormone therapy can bring out new moles and darken existing ones. Sun-exposed skin develops more of them. The count usually settles by about 30, so a pigmented spot that appears for the first time in your forties or fifties should be examined, because a substantial share of melanomas begin as a new lesion and because the look-alikes of that age need to be told apart.

Why do I have so many moles?

How many moles you have is strongly inherited, and childhood sun exposure adds to the number. Most adults have 10 to 50. Having many more is common, and no single mole is abnormal because of it. It does change the risk picture: a 2005 meta-analysis found that people with more than 100 common moles carry several times the melanoma risk of people with fewer than 15. A high mole count is a reason to learn the ugly duckling sign, to self-check monthly, and to have periodic full-skin examinations.

Do moles change with age, pregnancy or sun exposure?

Yes, and the pattern of the change is what matters. Sun darkens moles evenly and temporarily. Pregnancy and hormone therapy can darken and enlarge many moles at once, symmetrically and modestly, and the change settles after delivery. From the fifties onward moles fade, flatten or disappear, which is normal. A single mole that changes asymmetrically, quickly or in a different way from your others is examined on the same terms at any age, including during pregnancy, when a real change is easily attributed to hormones and left.

Can a mole disappear on its own?

Yes. From the fifties onward the mole count falls, and individual moles lose colour, flatten or vanish gradually over years. In teenagers and young adults a mole sometimes develops a pale ring of skin around it, a halo naevus, and then fades over months to years without treatment. Both are benign patterns. A mole that disappears quickly, leaves an irregular or discoloured patch behind, or develops a new white or grey area inside it is examined, because loss of pigment can also mean an immune response to something abnormal.

Is a raised mole more dangerous than a flat one?

No. Most raised moles are intradermal naevi, with the pigment cells sitting in the deeper layer of skin, and they are almost always benign. Elevation on its own says little about risk. What matters is a change in elevation: a flat mole that becomes raised over weeks or months, or any raised lesion that is firm and visibly growing, is examined promptly, because that is how nodular melanoma behaves. Nodular melanoma can be small, symmetrical and a single colour, so growth and firmness are the signs to act on.

References

1. Abbasi NR, Shaw HM, Rigel DS, et al. Early diagnosis of cutaneous melanoma: revisiting the ABCD criteria. JAMA 2004;292(22):2771-2776.

2. Grob JJ, Bonerandi JJ. The “ugly duckling” sign: identification of the common characteristics of nevi in an individual as a basis for melanoma screening. Arch Dermatol 1998;134(1):103-104.

3. Ilyas M, Costello CM, Zhang N, Sharma A. The role of the ugly duckling sign in patient education. J Am Acad Dermatol 2017;77(6):1088-1095.

4. Sng J, Koh D, Siong WC, Choo TB. Skin cancer trends among Asians living in Singapore from 1968 to 2006. J Am Acad Dermatol 2009;61(3):426-432.

5. Gandini S, Sera F, Cattaruzza MS, et al. Meta-analysis of risk factors for cutaneous melanoma: I. Common and atypical naevi. Eur J Cancer 2005;41(1):28-44.