Moles: Information for Patients

Summary in 60 seconds

Most moles are benign and can stay with you for many years.

• “Mole” usually refers to a melanocytic nevus : a group of pigment-producing cells (melanocytes).
• There are congenital moles (present from birth or early years) and acquired moles (appearing mainly in childhood and young adulthood).
• The most important reason to seek medical advice is not «having moles», but seeing changes : size, shape, color, relief or symptoms.
• Useful warning signs: ABCDE ( A symmetry, Irregular edges , Varied color , “striking” diameter , E evolution) and the “ugly duckling” sign (one looks different from the rest).
• Consult a dermatologist if a new mole appears in adulthood that grows or changes , or if a mole bleeds, hurts, persistently itches, ulcerates, or does not heal .

What are they and why is it important to monitor them?

A mole is a common skin lesion. In medicine, many moles are classified as melanocytic nevi , that is, clusters of melanocytes (cells that produce melanin, the pigment that gives skin its color). Depending on age and the individual, they can be flat or raised, lighter or darker, and even the same color as the skin.

They are important because, although the vast majority are benign, they can sometimes develop into skin cancer (melanoma). Therefore, monitoring focuses on changes and symptoms , not on fear.

What are they about?

Moles appear due to a combination of individual predisposition (genetics) and environmental factors . In many people, the number of moles increases from childhood to early adulthood and then tends to stabilize or decrease over the years. UV exposure and sunburn are associated with the appearance of new moles in some susceptible individuals. British Association of Dermatologists 2021 .

Key point: skin changes over time. The important thing is to recognize which changes are expected (for example, small, slow variations) and which ones warrant evaluation without unnecessary delay .

Types of moles: the most common (explained simply)

You don’t need to memorize categories, but you do need to understand that «molar» is not just one thing.

1. Common acquired moles
   They usually appear in childhood and young adulthood. They are often symmetrical, with a relatively uniform color, and stable for years. They can be:

• • Flat (sometimes darker) planes .
  • Slightly elevated .
  • Raised and lighter (sometimes with hair).
    (General description consistent with patient guidelines: British Association of Dermatologists 2021 .

1. Congenital moles
   They are present from birth or appear in the first few years of life. They are classified by size (small, medium, large/“giant”). In general, small and medium-sized lesions are managed with observation; large lesions require dermatological follow-up due to a higher risk, although the absolute risk varies from case to case. Society for Pediatric Dermatology 2024 .

2. Atypical (dysplastic) moles
   They may be larger, have less regular borders, or be more than one color. Important: “atypical” does not mean “cancer,” but it can be associated with a higher risk and usually warrants more frequent monitoring, depending on the context. National Cancer Institute 2022 .

3. Other less frequent nevi (brief mention)
   Some moles may appear bluish (“blue nevus”), pinkish, or grow rapidly in children (“Spitz”), etc. Many are benign, but since they can be confused with other conditions, the rule of thumb is the same: if something is new, changes, or looks different from the rest, have it evaluated by a dermatologist .

How to monitor moles?

When it comes to moles, the key is to monitor them closely and consult a doctor in time .

1) Make a mind map of “what is normal for you”

• Do you have many moles? Do they look alike?
• Are there any that are clearly different (“ugly duckling”)?
• If there is one, it deserves a closer look from a dermatologist.

2) Check your skin using this method (5–10 minutes)

• Ideally once a month if you have many moles or a family history; otherwise, with reasonable regularity and whenever you notice something new.
  • Good light.
  • Full-length mirror + hand mirror.
  • Don’t forget: back, scalp (with help from another person), soles, between toes, nails.

3) Use simple alert rules (ABCDE + evolution)

• The ABCDE rule is a useful guide for remembering common signs:
  • Asymmetry: one half does not resemble the other.
  • B Edges: irregular, “jagged”, poorly defined.
  • C Color: various shades or color changes.
  • D Diameter: traditionally mentioned as >6 mm, but melanomas can be smaller; the important thing is that it is «noticeable» or changing.
  • Evolution: any change over weeks/months or that deviates from the usual pattern. American Cancer Society 2025 .

4) Document without obsessing

• A clear photo with a ruler next to it can help with comparison.

• If you’re unsure, the photo is not a substitute for a consultation; it’s just for reference.

Common mistakes

• Waiting for it to «hurt» : melanoma may not cause pain at first.

• Relying solely on size : small lesions can also be relevant Abbasi 2004 .

• Picking, shaving or “burning” a mole at home : can complicate the skin, increase the risk of infection and delay a diagnosis.

• Thinking that “if it’s present at birth, it’s untouchable” : many congenital moles are easily observed, but some require regular monitoring due to their size or changes. Society for Pediatric Dermatology 2024 .

• Assuming that everything dark is lunar : there are benign lesions that look similar (seborrheic keratosis, angiomas) and others that require evaluation.

Myths vs. Facts

Myth: “If a mole has hair, it’s never bad.”
Fact: Hair is usually seen in benign lesions, but it does not rule out a problem if there are changes, bleeding, or progression.

Myth: “All atypical moles become melanoma.”
Fact: Most do not progress to melanoma, but they can indicate a higher-risk profile and warrant monitoring. National Cancer Institute 2022 .

Myth: “If it doesn’t meet ABCDE, it’s not a problem.”
Fact: Some dangerous injuries do not follow the typical pattern; that’s why the «ugly duckling,» evolution, and symptoms matter (Duarte 2021 ).

When to consult? (when should a specialist assess it)

Consult your dermatologist if any of these occur:

Priority consultation (as soon as reasonable)

• A new mole or spot in adulthood that grows or changes . (In general, new moles in adulthood should be monitored and checked if they change: British Association of Dermatologists 2021 ).
• Clear evolution in weeks/months: changes in color, shape, relief or size.
• Sign of “ugly duckling” : one looks different from everyone else.

Urgent consultation

• Bleeding without a clear cause, persistent crusting , ulceration , suppuration.
• Persistent itching , pain, tenderness, or swelling not explained by a single touch. National Cancer Institute 2022 ; American Cancer Society 2025 .
• Injury that looks like a “wound” and does not heal within a reasonable time MedlinePlus 2026 .

If you are at higher risk, lower the consultation threshold.

• Personal or family history of melanoma.
• Many moles (for example, dozens) or several atypical ones.
• Immunosuppression or a history of severe sunburn. MedlinePlus 2026 .

What will the specialist do?

• During a consultation, the dermatologist usually:
  • Examine all of the skin (not just «that mole»).
  • Use dermatoscopy (magnifying glass with light) to see structures that are not visible to the naked eye.
  • Decide whether it is appropriate to: observe, photograph for follow-up, or perform a biopsy (the way to confirm diagnosis when there is suspicion).

Frequently Asked Questions

Is it normal to have many moles?

• Yes, many people have several. The important thing is to know your pattern and monitor for changes. If you have a lot of them or several atypical ones, more structured dermatological monitoring may be helpful.

Is it normal for new moles to appear in adults?

• It can happen, but in general a «new mole» in adulthood deserves more attention, especially if it grows or changes . British Association of Dermatologists 2021 .

What happens if I injure a mole and it bleeds?

• If it was a clear blow and heals well, it’s usually not serious. But if bleeding occurs without explanation, recurs, or a persistent scab remains, evaluation is advisable. National Cancer Institute 2022 .

Is the ABCDE rule sufficient?

• It’s a useful guide, but not perfect. Some relevant injuries don’t quite fit; that’s why the evolution and the «ugly duckling» Duarte 2021 are also important.

Is a raised mole worse than a flat one?

• Not necessarily. There are raised, benign moles and flat, worrisome lesions. The criterion is not the isolated raised area, but the overall picture: appearance, evolution, and symptoms.

Can moles be removed for cosmetic reasons?

• Sometimes it’s possible, but it must be done by a dermatologist (after a clinical evaluation and biopsy if there are atypical findings). Avoid home remedies or non-professional assessments at all costs.

What happens to congenital moles in children?

• Most children with congenital moles are healthy. Small to medium-sized moles are usually monitored; large or changing moles require dermatological follow-up. Society for Pediatric Dermatology 2024 .

Bibliography and sources

• British Association of Dermatologists. Melanocytic naevi (pigmented moles) [Internet] . London: British Association of Dermatologists; 2021 [consultado 6 jun 2026] . Available from: British Association of Dermatologists .
• National Cancer Institute. Common moles, dysplastic nevi, and risk of melanoma [Internet] . Bethesda (MD): National Cancer Institute; 2022 [consultado 6 jun 2026] . Available from: National Cancer Institute .
• American Cancer Society. Signs and symptoms of melanoma skin cancer [Internet] . Atlanta: American Cancer Society; 2025 [consultado 6 jun 2026] . Available from: American Cancer Society .
• National Comprehensive Cancer Network. NCCN Guidelines for Patients: Melanoma [Internet] . Plymouth Meeting (PA): National Comprehensive Cancer Network; 2021 [consultado 6 jun 2026] . Available from: NCCN .
• MedlinePlus. Skin cancer screening [Internet] . Bethesda (MD): National Library of Medicine; 2026 [consultado 6 jun 2026] . Available from: MedlinePlus .
• Abbasi NR, Shaw HM, Rigel DS, Friedman RJ, McCarthy WH, Osman I, et al. Early diagnosis of cutaneous melanoma: revisiting the ABCD criteria . JAMA. 2004;292(22):2771-2776. doi:10.1001/jama.292.22.2771.
• Duarte AF, Sousa-Pinto B, Azevedo LF, Barros AM, Puig S, Malvehy J, et al. Clinical ABCDE rule for early melanoma detection . Eur J Dermatol. 2021;31(6):771-778. doi:10.1684/ejd.2021.4171.
• Frischhut N, Zelger B, Andre F, Zelger BG. The spectrum of melanocytic nevi and their clinical implications . J Dtsch Dermatol Ges. 2022;20(4):483-504. doi:10.1111/ddg.14776.
• Society for Pediatric Dermatology. Congenital nevi [Internet] . Indianapolis: Society for Pediatric Dermatology; 2024 [consultado 6 jun 2026] . Available from: Society for Pediatric Dermatology .
• Krengel S, Hauschild A, Schäfer T. Melanoma risk in congenital melanocytic naevi: a systematic review . Br J Dermatol. 2006;155(1):1-8. doi:10.1111/j.1365-2133.2006.07218.x.