Most moles are harmless—but some can be early signs of skin cancer. Knowing how to check a mole can help you spot warning signs early and decide when to see a doctor.
This guide covers a simple 5-step self-check you can do at home, using the same criteria dermatologists use. Early detection matters: the 5-year survival rate for melanoma caught early is over 99%.
5-Step Mole Self-Check
Look at All Your Moles
Before focusing on one spot, look at all your moles together.
Most people have a 'mole pattern'—similar size, color, and shape across their moles. A mole that looks different from the rest deserves attention. This is called the ugly duckling sign.
Use a full-length mirror and check your entire body, including hidden areas.
Use the ABCDE Rule
Check each suspicious mole against five key criteria.
Dermatologists use these five warning signs to identify potential melanoma: Asymmetry (halves don't match), Border irregularity (jagged or blurry edges), Color variation (multiple colors), Diameter over 6mm (pencil eraser size), and Evolution (any change).
Learn more in our complete ABCDE guide.
Read full guideWatch for Change
The single most important warning sign is evolution.
Pay close attention if a mole: grows quickly, darkens or fades, becomes raised, starts itching or bleeding, or develops crust or a sore. Any change over weeks to months should be evaluated.
Take monthly photos to track subtle changes over time.
Look for Red Flags
Some signs require urgent professional evaluation.
See a doctor promptly if a mole: bleeds or oozes without injury, becomes painful, changes over weeks or months, looks unlike your other moles, develops multiple colors, or appears under a nail or on the sole of the foot.
Don't panic—but don't wait if you notice these signs.
Take a Clear Photo
Good photos help you track changes and use screening tools.
Use bright natural light, focus clearly, include a coin or ruler for scale, take from 2 angles, and avoid filters. Store photos with dates so you can compare over time.
AI screening tools like ScanSkinAI can analyze your photos instantly.
Why one check is rarely enough
A single scan tells you about one spot, on one day. But skin changes are about patterns over time — a new mole appearing, a slow shift in shape, size or colour, or a patch that simply isn't healing. Monitoring the same spots side-by-side, week after week, surfaces the subtle changes a one-off check will always miss — and gives you a clear record to show a clinician if something needs a closer look.
(ScanSkinAI is a screening and monitoring tool, not a diagnosis. Always see a clinician for anything that is changing, bleeding, or worrying you.)
Track your skin over time — 3 months unlimitedRelated reading: How to track moles over time · ABCDE rule for melanoma
Urgent Warning Signs
See a doctor urgently if a mole shows any of these signs:
- Bleeds or oozes without injury
- Becomes painful
- Changes rapidly over weeks or months
- Looks distinctly different from all your other moles
- Develops multiple colors (especially red, white, or blue)
- Appears under a fingernail or toenail
- Located on the sole of the foot or palm
What Changes Matter Most
Evolution is the most important warning sign. Any mole that changes should be evaluated. Particularly concerning changes include:
- A mole that grows larger over weeks or months
- A mole that develops new colors (especially red, white, or blue)
- A mole that starts bleeding, oozing, or crusting
- A mole that becomes itchy, tender, or painful
- A new mole appearing after age 30
The key is comparison over time—monthly photos help you spot subtle changes that might otherwise go unnoticed.
Photo Guide for Tracking
Good photos help you track changes and use online screening tools. Follow these tips:
Store photos with dates (e.g., "left_arm_mole_jan2025.jpg") so you can compare month-to-month.
When to See a Dermatologist
Schedule an appointment if you notice:
- Any mole showing one or more ABCDE warning signs
- Any mole that is changing over weeks or months
- A mole that looks different from all your other moles
- A new mole appearing after age 30
- A mole that bleeds, itches, or becomes painful
Remember: most moles that are checked turn out to be benign. The goal is early detection of the rare melanoma, when treatment is most effective.
Learn More
Frequently Asked Questions
Medical Disclaimer
This guide is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. If you have concerns about a mole, consult a qualified dermatologist. AI screening tools can help identify moles that may need professional evaluation but cannot provide medical diagnoses.