A practical, step-by-step guide to self-exams and the signs that warrant a visit
Most people have heard of the "ABCDEs" for spotting a suspicious mole — but basal cell carcinoma (BCC) rarely looks like a mole at all. It's far more likely to show up as a small shiny bump, a sore that keeps opening back up, or a patch of skin that just doesn't look quite right. That mismatch is one reason BCCs sometimes go unnoticed for months: people are watching for the wrong thing.
The good news is that BCC grows slowly and its warning signs, once you know them, are fairly consistent and easy to check for yourself at home. This guide walks through exactly how to do a self-exam, what BCC actually looks like at different stages, and the specific point at which "I should keep an eye on that" becomes "I should call my dermatologist."
Pick a well-lit room and do this roughly once a month — right after a shower is a good habit to build it into. You'll need a full-length mirror and a hand mirror.
Pay closest attention to sun-exposed areas — the face, ears, neck, scalp, shoulders, and back of the hands — since roughly 80% of BCCs develop there. But don't skip less sun-exposed skin entirely; it's less common, not impossible.
Unlike melanoma, BCC doesn't usually present as a pigmented, mole-like spot, so the ABCDE checklist doesn't map onto it well. Instead, dermatologists describe BCC as showing up in one of a few recognizable patterns:
A small, dome-shaped bump that looks translucent or waxy — pink, red, or white on lighter skin, and often brown, black, or glossy on deeper skin tones. Fine blood vessels are sometimes visible across its surface. This is the most classic presentation, called nodular BCC.
An open area that bleeds, oozes, or crusts, appears to heal, and then reopens — sometimes over weeks or months. A sore that keeps cycling through this pattern instead of fully healing is one of the more reliable warning signs, and one of the most commonly missed, since it's easy to mistake for a scab or minor injury.
A flat or slightly scaly pink-to-red patch, often on the chest, shoulders, arms, or legs, that may itch or feel tender but sometimes causes no sensation at all. This superficial pattern is easy to dismiss as eczema, a rash, or dry skin.
A firm, waxy, white or yellowish patch with skin that looks stretched or shiny, and a border that's hard to pinpoint. This pattern (morpheaform BCC) is the easiest to miss on self-exam precisely because it doesn't look like a typical growth — it looks like a scar you don't remember getting. See our guide to BCC types for more on how these patterns relate to how the cancer behaves.
You don't need to be certain something is BCC before getting it checked — that's your dermatologist's job. Book an appointment if you notice:
Normal skin injuries heal within a couple of weeks. A sore, bump, or patch that persists, keeps crusting over and reopening, or bleeds without an obvious cause has gone past what's typical for healing and is worth evaluating.
BCC typically grows slowly, over months, so "it's been getting a little bigger" over a few visits to the mirror is a meaningful change, not something to wait out.
Dermatologists sometimes call this the "ugly duckling" sign — a spot that simply stands out from the pattern of everything else on your skin, even if you can't articulate exactly why, is worth a second opinion.
A history of significant sun exposure or blistering sunburns, fair skin, a prior BCC or other skin cancer, older age, or immunosuppression all raise your odds of developing BCC. If several apply to you and it's been over a year since a professional skin check, it's worth scheduling one even without a specific spot in mind.
It's worth noting that national screening guidelines currently say the evidence is insufficient to recommend for or against routine full-body skin exams by a primary care doctor in people with no symptoms or risk factors. That's a statement about population-wide screening programs, though — it doesn't apply to you personally noticing a specific changing spot, which is exactly the situation where getting checked has clear value.
A monthly self-exam takes a few minutes and doesn't require any special equipment — just a mirror and a habit. Knowing that BCC tends to show up as a shiny bump, a non-healing sore, a reddish patch, or a scar-like area, rather than a changing mole, makes it much easier to catch early.
When in doubt, get it looked at. BCC is highly treatable, and the earlier it's caught, the simpler that treatment tends to be.
Disclaimer: This article is for educational purposes only and not a substitute for professional medical advice. Always consult a qualified dermatologist about any changes to your skin.
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