A thorough skin self-exam takes about 10 to 15 minutes and can meaningfully reduce your risk of advanced melanoma. One large case-control study found that people who regularly examined their own skin had a 63% lower risk of dying from melanoma compared to those who didn’t. You don’t need any special equipment, just good lighting, a full-length mirror, a hand mirror, and your phone camera.
What You Need Before You Start
Good lighting makes or breaks a skin check. Natural light from a window is ideal, but your phone’s flashlight works well for hard-to-see spots like under your hair, between your toes, or inside your armpits. You’ll want a full-length mirror and a hand mirror so you can see your back, the backs of your legs, and your scalp.
Your phone camera is one of the most useful tools you have. During each self-exam, photograph any spots, moles, or freckles you want to track over time. Place a dime or pencil eraser next to the spot for scale, and take one photo with flash and one without to capture color accurately. Create a dedicated album on your phone and label each image descriptively (“left shoulder mole,” “right ankle freckle”). This photo log becomes invaluable when you’re trying to decide months later whether something has actually changed or just looks different today.
A Head-to-Toe Routine
Work in a consistent order every time so you don’t skip areas. Start by facing the full-length mirror and scanning the front of your body: face, neck, chest, abdomen, and legs. Then turn and check both sides, raising each arm to see your torso and the insides of your upper arms. Use the hand mirror to examine the back of your neck, your back, buttocks, and the backs of your legs.
Sit down for the lower half. Check the tops and soles of both feet, and look between every toe. Examine your palms and the backs of your hands, then bend each arm to inspect both sides of your forearms and the backs of your upper arms, an area people commonly miss. For your scalp, use a comb to part your hair in sections while angling the hand mirror. Ask someone you trust to help with your scalp, back, and any other areas you can’t see clearly on your own. Don’t skip your genital area or the skin between your buttocks.
The ABCDE Rule for Melanoma
The ABCDE framework is the standard tool dermatologists recommend for evaluating moles. Each letter flags a different warning sign.
- Asymmetry: One half of the mole doesn’t match the other. A normal mole is roughly symmetrical.
- Border: The edges are ragged, notched, or blurred rather than smooth. Pigment may spread into surrounding skin.
- Color: Multiple shades are present within the same spot. Look for mixtures of black, brown, tan, white, gray, red, pink, or blue.
- Diameter: Most melanomas are larger than 6 millimeters across, roughly the size of a pencil eraser. But melanomas can start smaller, so size alone isn’t definitive.
- Evolving: The mole has changed in size, shape, or color over the past few weeks or months. This is often the most important sign.
Any single one of these features is worth noting. Two or more together make a stronger case for getting it looked at professionally.
The Ugly Duckling Sign
If you have many moles or freckles, the ABCDE criteria can feel overwhelming because you’re evaluating each spot in isolation. The ugly duckling sign offers a faster, pattern-based approach: look for the one mole that doesn’t match the rest. Most of your moles will share a general family resemblance in color, size, and shape. If one spot stands out from its neighbors, whether it’s darker, more raised, scabbed over, or just different, that’s the one to photograph and monitor closely.
Signs Beyond Moles
Melanoma gets the most attention, but two other skin cancers are far more common: basal cell carcinoma and squamous cell carcinoma. These don’t follow the ABCDE pattern and look quite different.
Squamous cell carcinoma often appears as a firm bump or nodule that can be pink, red, brown, or skin-colored. It may also show up as a flat sore with a scaly crust, a rough patch on your lip, or a new raised area on an old scar. Inside the mouth, it can look like a sore or rough patch that doesn’t resolve. The key warning sign for both basal and squamous cell carcinoma is a sore or scab that doesn’t heal within about two months. Any persistent, non-healing wound on sun-exposed skin deserves attention, even if it doesn’t look like a typical mole.
Skin Cancer on Darker Skin
Skin cancer looks different on darker skin tones, and it tends to appear in locations people don’t think to check. The most common type of melanoma in people of color is acral lentiginous melanoma, which develops on the palms, soles of the feet, or under the nails rather than on sun-exposed areas.
On the palms or soles, it looks like a black or brown discoloration that may resemble a bruise or stain. The difference is that it grows in size over time instead of fading. Under the nails, it typically appears as dark vertical streaks or discolorations running the length of the nail bed. As it progresses, it can cause the nail to crack or break. This is sometimes mistaken for a fungal infection or a blood blister from an injury. If you have a dark streak under a nail that wasn’t caused by trauma and doesn’t grow out as the nail grows, get it evaluated.
Symptoms That Need Prompt Attention
Beyond visual changes, pay attention to how your skin feels. A mole that persistently itches, bleeds, or becomes tender could signal a problem, especially if it developed after age 30. Oozing, a red rash around a mole, or swelling are additional flags. Rapid growth over a period of weeks is particularly concerning. None of these symptoms guarantee cancer, but they all warrant a dermatologist’s evaluation rather than a wait-and-see approach.
How Often to Check
The American Academy of Dermatology recommends performing regular skin self-exams as a routine part of your health care. Most dermatologists suggest monthly checks, which is frequent enough to notice changes early but not so frequent that every exam blurs together. Picking a consistent day, like the first of the month, helps it become a habit.
Your self-exams are genuinely useful, but they have limits. Research shows that a well-instructed person can count and track moles with reasonable accuracy, with sensitivity between 57% and 79%. But untrained patients struggle to distinguish atypical moles from normal ones. Professional skin exams catch thinner, earlier-stage melanomas on average. In one study from a major cancer center, melanomas found by physicians had a median thickness of 0.23 mm compared to 0.9 mm for self-detected ones. Thinner melanomas have dramatically better outcomes. So monthly self-exams are a powerful complement to periodic professional screenings, not a replacement for them.