By SpotCheck Clinical Staff
Skin cancer is the most common cancer in the United States, but it's also one of the most treatable—especially when it's found early. As a Mohs surgeon, I often meet patients who noticed a change on their skin weeks or months earlier but weren't sure whether it was important.
This guide will help you understand the early signs of skin cancer in a way that's practical and easy to remember.
The three most common forms of skin cancer behave differently and often look different.
Basal cell carcinoma is the most common and usually grows slowly. These often appear on sun-exposed areas like the face, scalp, and ears.
Squamous cell carcinoma is somewhat more aggressive and may grow faster or become tender.
Melanoma is less common but more dangerous. It develops from pigment-producing cells and can appear almost anywhere on the body—even in places that rarely see the sun.
Most skin cancers start subtly. One of the earliest warning signs is a spot that simply doesn't heal. People often describe a place that scabs, flakes, or bleeds, then seems to "heal" for a few days before breaking open again. Anything that behaves like a wound for more than a month deserves a professional look.
Changes in texture can also be important. A patch of skin that becomes rough, scaly, or persistently irritated may represent an early squamous cell cancer or a precancerous lesion. These areas sometimes feel like a small piece of sandpaper that keeps returning to the same spot.
Another reason to get checked is growth that feels out of proportion. Skin cancers—especially squamous cell carcinomas—may enlarge over several weeks. A bump that becomes noticeably bigger in a short period of time, or becomes painful or tender, should be evaluated.
With moles, the most important thing is change. Dermatologists often refer to the "ABCDE" features (asymmetry, border irregularity, color variation, diameter, and evolution), but evolution—meaning any shift in size, shape, color, or symptoms—is usually the most important sign. Even a small mole can be concerning if it's changing.
Skin cancer doesn't always occur where you expect it. While sun-exposed areas like the nose, cheeks, scalp, and ears are common, melanoma can appear in less obvious places. Dark streaks under a nail, new pigmented spots on the palms or soles, or lesions in areas with little sun exposure may represent melanoma and should not be ignored.
Chronic wounds or scars can also be sites where skin cancers develop, particularly squamous cell carcinoma. If an old injury starts to change or becomes persistently irritated, it's worth being examined.
Anyone can develop skin cancer, but the risk is higher for individuals with a history of extensive sun exposure, fair skin, or prior skin cancer. People with weakened immune systems—such as organ transplant recipients—also tend to develop more aggressive skin cancers. And while lighter skin types are at greater risk overall, melanoma in darker skin often appears in areas like the palms, soles, and nails, where it may be overlooked.
You don't have to know whether something is cancerous—that's our job. But if you notice a spot that looks new, is changing, isn't healing, or just feels "off," it's a good time to seek a dermatology evaluation. Most concerning spots turn out to be harmless, and many serious ones are discovered by patients who simply trusted their instincts.
Skin cancer is most treatable when caught early. Paying attention to small changes—especially something that doesn't heal, keeps coming back, or looks different from the surrounding skin—can make a tremendous difference. A quick visit with a dermatologist can provide clarity, reassurance, and, when necessary, prompt treatment.