Checking your skin, and having a professional check it, is one of the most valuable habits in skin health. Most spots are harmless, but noticing change early is what matters most. This guide explains the widely taught ABCDE warning signs, how to do a simple self-exam, and what a professional screening involves — while stressing that only a dermatologist can evaluate a specific spot, and anything worrying deserves prompt attention.
The short version
The ABCDE guide is a simple memory aid for warning signs in a mole.
Change over time is one of the most important things to watch for.
A self-exam is useful, but it does not replace a professional check.
People with risk factors may benefit from regular professional screenings.
Anything new, changing, or non-healing deserves prompt professional evaluation — do not wait.
The ABCDE guide
The ABCDE guide is a commonly taught way to remember warning signs worth a professional look. It is a prompt to seek evaluation, not a diagnostic test.
Letter
Stands for
What to notice
A
Asymmetry
One half does not match the other
B
Border
Edges that are irregular, ragged, or blurred
C
Color
More than one color, or uneven color
D
Diameter
Larger spots, though small ones can matter too
E
Evolving
Any change in size, shape, color, or feel over time
Of these, the “E” — evolving — is often emphasized, because change is a signal that something is worth checking regardless of the other letters. A sore that does not heal, or a spot that itches or bleeds, is also worth professional attention.
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Doing a simple self-exam
A self-exam is a habit you can build at home. In good light, with a mirror and ideally a partner to check hard-to-see areas, look over your skin systematically — face, scalp, neck, torso, arms, hands, legs, feet, between toes, and the back. The goal is not to diagnose anything; it is to get familiar with what is normal for you so you notice when something changes. Photos can help you compare over time.
Pro tip — use the “ugly duckling” idea
Most of a person’s moles tend to look similar to one another. A spot that stands out as different from the rest — the “ugly duckling” — is worth pointing out to a dermatologist, even if it does not tick every ABCDE box.
How a professional screening works
A professional skin cancer screening is a visual head-to-toe exam by a dermatologist, often with a handheld magnifier called a dermatoscope for a closer look at specific spots. It is quick and painless. If the dermatologist sees something that warrants further evaluation, they may recommend a biopsy — taking a small sample to examine under a microscope, which is the way a definitive answer is reached. A biopsy is a normal next step, not a cause for alarm on its own.
Who benefits from regular checks
How often to be screened is an individual decision made with a dermatologist, because it depends on your risk factors. People often considered higher risk include those with significant sun exposure over the years, a history of sunburns, many moles, fair skin that burns easily, or a personal or family history of skin cancer. If any of that describes you, it is worth asking a professional what screening schedule makes sense.
Why early attention matters
The single most useful message about skin cancer is that noticing change early and getting it evaluated promptly is what counts. That is why building the habit of self-checks, combined with professional screening when appropriate, is so valuable. If something is new, changing, or simply does not look right to you, do not wait to see if it goes away — have it looked at.
Have a spot you want checked?
Browse and compare dermatologists near you on Dermatologists At Your Service.
Can I diagnose skin cancer myself with the ABCDE guide?
No. The ABCDE guide is a prompt to seek professional evaluation, not a diagnosis. Only a dermatologist can properly assess a spot, and a biopsy is often what gives a definitive answer. Use ABCDE to decide when to book, not to reassure yourself something is fine.
How often should I have a professional skin check?
It varies with your individual risk factors. Some people benefit from an annual screening, others more or less often. A dermatologist can recommend a schedule based on your history and risk.
Does a mole check hurt?
The exam itself is visual and painless. If a biopsy is recommended, the area is numbed first, so you feel a brief pinch and then pressure rather than pain.
What if I notice a mole changing between checks?
Do not wait for your next scheduled visit. A new or changing mole, or a sore that will not heal, is worth booking a prompt appointment. Describe the change clearly when you call so the office can prioritize appropriately.
General educational information only — NOT medical advice, diagnosis, or treatment. Always consult a licensed dermatologist or physician about your skin and health. Treatments, costs, and insurance coverage vary.
