Skin Self-Exam: How to Check Your Skin and the ABCDEs of Melanoma
Updated: 2 days ago
Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: November 2026 · How we review
Quick Answer
A skin self-exam is a head-to-toe check of your own skin, ideally once a month, to spot new or changing moles and other signs of skin cancer early. For moles, follow the ABCDEs of melanoma: Asymmetry, Border, Color, Diameter and Evolving. See a provider promptly for any spot that changes, bleeds, itches or doesn't heal.
What the research says
Self-exams catch many, but not all, suspicious spots: a meta-analysis of 3 studies and 553 people found skin self-examination detected suspicious pigmented lesions with 59% sensitivity and 82% specificity compared with a clinician's exam, so it complements, rather than replaces, professional skin checks (Jiyad Z et al., Dermatology, 2022) [2]
Photos and apps may help: a systematic review of 20 studies found digital visual aids such as smartphone apps and websites improved how often and how thoroughly people checked their skin, and 3 of 7 studies that measured it found more skin cancers detected (Abdalla H et al., Health Education & Behavior, 2026) [3]
Key takeaways
Check your whole skin once a month, after a shower, in a bright room.
Use a full-length mirror, a hand mirror and a blow dryer or comb for the scalp.
Use the ABCDEs and the ugly duckling sign to judge moles.
Take photos to track changes over time.
See a provider for any new, changing, bleeding, itching or non-healing spot.
Why do a skin self-exam?
Skin cancer is the most common cancer, and most types, including melanoma, are highly treatable when found early. You know your skin better than anyone, and checking monthly helps you notice changes between professional exams. Self-exams are especially important if you have many moles, atypical moles, fair skin, a history of sunburns or tanning beds, a weakened immune system or a personal or family history of skin cancer. Sources: [1]
A full skin check takes about 10–15 minutes.
The ABCDEs of melanoma
Use the ABCDEs to judge moles during a self-exam.
Letter | Warning sign | What to look for |
A | Asymmetry | One half doesn't match the other |
B | Border | Edges are ragged, notched or blurred |
C | Color | Uneven color, with shades of brown, black, red, white or blue |
D | Diameter | Larger than a pencil eraser (about 6 mm), though melanomas can be smaller |
E | Evolving | Any change in size, shape, color, height or new symptoms |
The ugly duckling sign is just as useful: most of your moles look alike, so a mole that looks different from the others deserves a check, even if it doesn't meet the ABCDE criteria. Some melanomas, such as amelanotic melanoma, are pink or skin-colored, so watch for any new spot that grows. Sources: [1]
How to do a skin self-exam
Stand in front of a full-length mirror in a bright room and look at your face, ears, neck, chest and belly. Lift breasts to check underneath.
Check the front and back of your arms, underarms, hands, palms, fingers and under your fingernails.
Look inside your mouth and at your lips.
Use a hand mirror to check the back of your neck, shoulders, upper back, lower back and buttocks.
Sit down and check the front and back of your legs, the tops and soles of your feet, between your toes and under your toenails.
Use a hand mirror to check your genital area.
Part your hair with a comb or blow dryer to check your scalp, or ask someone to help.
Note or photograph any spots so you can compare next month. Sources: [1]
Other skin cancers look different from melanoma: basal cell carcinoma often appears as a pearly or waxy bump or a sore that bleeds and heals repeatedly, and squamous cell carcinoma as a rough, scaly patch or firm red bump. Sources: [1]
How accurate is a self-exam?
Research suggests self-exams pick up roughly 6 in 10 suspicious spots that a clinician would flag, and correctly reassure about 8 in 10 normal ones. That makes them a useful early warning, not a replacement for a professional skin check if you're at higher risk. Taking photos, using apps or setting reminders can make your checks more thorough. Sources: [2, 3]
When to see a provider
Get any spot that changes checked promptly.
A new mole or spot, especially after age 30.
A mole that changes in size, shape, color or height.
A spot that itches, hurts, bleeds or crusts.
A sore that doesn't heal within a few weeks.
A mole that looks different from your others.
A dark streak under a nail. Sources: [1]
Your provider will examine the spot, often with a dermatoscope, and may remove a sample with a skin biopsy to check for cancer cells. Sources: [1]
Preventing skin cancer
Use a broad-spectrum sunscreen with SPF 30 or higher, reapply every two hours outdoors, seek shade between 10 a.m. and 4 p.m., wear protective clothing, hats and sunglasses, and avoid tanning beds. Sources: [1]
Conclusion
A monthly skin self-exam takes about 10–15 minutes and can help you find skin cancer early, when it is easiest to treat. Use the ABCDEs and the ugly duckling sign, photograph spots you want to watch, and don't wait to get any change checked.
Keep learning: read about melanoma and atypical moles.
Frequently asked questions
How often should I do a skin self-exam?
Once a month is recommended.
What are the ABCDEs of melanoma?
Asymmetry, Border irregularity, Color variation, Diameter larger than a pencil eraser and Evolving (changing).
What is the ugly duckling sign?
A mole that looks different from your other moles, which should be checked even if it doesn't fit the ABCDEs.
Can melanoma be smaller than a pencil eraser?
Yes. Size is only one clue; any changing or unusual spot should be checked.
Do I need to check areas that don't get sun?
Yes. Skin cancer can appear on the scalp, soles, between toes, under nails and in the genital area.
How accurate are skin self-exams?
They pick up about 6 in 10 suspicious spots, so they complement professional exams rather than replace them.
Should I take photos of my moles?
Yes. Photos make it easier to notice changes over time.
Who should get professional skin checks?
People with many or atypical moles, fair skin, a history of sunburns or a personal or family history of skin cancer; ask your provider how often.
What does skin cancer look like besides moles?
A pearly bump, a scaly patch, a firm red bump or a sore that won't heal.
What happens if a spot looks suspicious?
Your provider examines it and may do a skin biopsy to check for cancer.
Related Reading
Melanoma: A Comprehensive Guide to Early Detection and Treatment the skin cancer the ABCDEs help detect.
Dysplastic Nevus (Atypical Moles): What They Look Like, Your Melanoma Risk and What to Do Next moles that need closer watching.
What Is Basal Cell Carcinoma? Symptoms, Causes, and Treatment the most common skin cancer.
Skin Biopsy: Types, What to Expect, Results and Aftercare the test that confirms a suspicious spot.
Amelanotic Melanoma: The Skin Cancer That Hides in Plain Sight — What It Looks Like, Why It's Missed, and How It's Treated a melanoma that doesn't look dark.
References
Cleveland Clinic. ABCDEs of Melanoma: Warning Signs of Skin Cancer. Cleveland Clinic. Last updated August 26, 2025. https://my.clevelandclinic.org/health/diagnostics/8648-skin-self-exam
Jiyad Z, Plasmeijer EI, Keegan S, et al. Defining the validity of skin self-examination as a screening test for the detection of suspicious pigmented lesions: a meta-analysis of diagnostic test accuracy. Dermatology. 2022;238(4):640-648. PMID 34979506. https://doi.org/10.1159/000520592
Abdalla H, Joyce J, Hussain NAB, et al. Do digital visual aids improve skin self-examination behaviours? A systematic review. Health Education & Behavior. 2026. PMID 42626913. https://doi.org/10.1177/10901981261479324
Medical disclaimer
This article is for general education only and does not replace advice from a qualified healthcare professional. Talk to your doctor about your own diagnosis and treatment, and seek emergency care right away for severe or sudden symptoms.
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