Moles and Freckles (Nevus & Ephelis) — Differences, Risks and Proper Care
Moles and freckles are common on the skin of most people and are usually harmless. What deserves attention is the chance that some moles change into Melanoma, a skin cancer that can be dangerous if it is not detected in time. Understanding the difference between moles and freckles, and knowing how to spot an unusual mole, is an important skill for looking after your own skin.
What are moles and freckles?
Moles (Nevus): A mole (Nevus) is a cluster of pigment cells called Melanocytes in the skin. It may be present from birth (Congenital Nevus) or appear later in life (Acquired Nevus).
Freckles: Freckles, also called Ephelis, form when melanin builds up in skin cells without an increase in the number of cells. Freckles become darker with sun exposure and fade in winter.
How to spot a dangerous mole — the ABCDE rule
Dermatologists use the ABCDE rule to assess the risk of a mole that may be cancerous.
A: Asymmetry — the two halves of the mole do not match
B: Border — the edge is uneven
C: Color — the color is not uniform, with more than one shade
D: Diameter — wider than 6 millimeters
E: Evolving — changes in color, size or shape
How moles differ from freckles
Moles: Usually brown or black, either raised or flat. They generally stay the same and cause no other symptoms. Moles do not fade even when kept out of the sun.
Freckles: Small brown spots that darken with sun exposure and fade in the shade, so unlike moles, they can lighten.
Treatment and prevention
Normal moles: Ordinary moles do not need treatment.
Unusual moles: If a mole looks unusual according to the ABCDE rule, the doctor will consider removing a sample for examination under the microscope (Biopsy).
Prevention: The best protection is to apply sunscreen of SPF 30 or higher every day and to check your moles regularly, at least once a year, especially if you have many moles or a mole is changing.
Frequently asked questions
How are moles different from freckles? A mole (Nevus) is a cluster of pigment cells. It is usually brown or black, may be raised or flat, and does not fade even when kept out of the sun. Freckles form when melanin builds up without an increase in the number of cells, and they darken with sun exposure and fade in the shade.
How can I tell if a mole is dangerous? Use the ABCDE rule: Asymmetry, Border (uneven edge), Color (more than one shade), Diameter (wider than 6 millimeters) and Evolving (changing). If a mole has these features, see a doctor for an assessment.
Does a mole that changes need to be removed? If a mole changes according to the ABCDE rule, the doctor may consider removing a sample for examination under the microscope (Biopsy) to confirm that it is not cancer. An assessment by a dermatologist is therefore important.
How can I prevent moles and skin cancer? The best protection is to apply sunscreen of SPF 30 or higher every day, avoid strong sunlight, and check your own moles regularly, at least once a year, especially if you have many moles.
Most moles and freckles are harmless, but watching them with the ABCDE rule and protecting your skin from the sun regularly can help lower the risk of skin cancer. If you notice a mole that is changing or looks suspicious, consult a dermatologist at Siam Dermatology. Call +66 61 448 7000 or LINE @siamderm.
Written by Dr. Patara Voravutinon, Dermatologist · Last reviewed July 16, 2026
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