Signs of Skin Cancer - Spot, Treat, and Prevent Early

Catching the signs of skin cancer early can save your life.

It’s also one of the simplest health habits you can build: learn what to look for, check your skin monthly, and act fast on anything new, changing, or unusual.

Skin cancer is the most common cancer globally, and in the U.S. an estimated 1 in 5 people will develop it by age 70. Routine self-checks and professional exams dramatically increase the chances of detecting cancers when they’re easily treated.

Early Signs of Skin Cancer (What to Look For)

For moles and dark spots, remember the ABCDEs of melanoma—a simple screening tool recommended by the American Academy of Dermatology (AAD):

A – Asymmetry: One half doesn’t match the other.
B – Border: Edges are irregular, scalloped, or poorly defined.
C – Color: Varies from one area to another (tan, brown, black, white, red, or blue).
D – Diameter: Larger than 6 mm (pencil eraser)—but small melanomas occur, too.
E – Evolving: Any change in size, shape, color, elevation, or new symptoms like bleeding or itching.

Use the “ugly duckling” rule as well: a spot that looks different from your other moles deserves attention. New growths after age 30, a sore that doesn’t heal in 3–4 weeks, or any mole that starts itching, bleeding, or crusting are reasons to book a skin exam. The Skin Cancer Foundation provides helpful self-exam visuals and guides.

Not all skin cancers are dark or obvious. Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) often look like everyday skin issues. If a spot keeps recurring, bleeds easily, or slowly enlarges, get it checked.

Possible BCC signs: Pearly or translucent bump, pink shiny patch, a sore that heals and returns, or a scar-like area without injury.
Possible SCC signs: Scaly red patch, rough thickened or wart-like growth, open sore, or a firm, tender nodule; can arise on sun-damaged skin or lips.
Melanoma can be sneaky: It may appear under nails, on the scalp, or on the soles; look for a dark streak in a nail not linked to trauma.

When to see a dermatologist—fast

A spot that’s evolving rapidly (weeks to months).
A sore that won’t heal, keeps bleeding, or crusts repeatedly.
A new mole after age 30 or a mole that looks different from the rest.
Any lesion accompanied by pain, itching, or tenderness that persists.

How Skin Cancer Is Diagnosed

A dermatologist will assess concerning spots using a bright light and often a dermatoscope (a handheld magnifier). If cancer is suspected, the next step is a skin biopsy, where a small sample is removed and analyzed under a microscope.

Pathology results identify the type (e.g., BCC, SCC, melanoma) and key details like depth and margins. These guide treatment choices. For melanoma, your doctor may also discuss staging tests and, in some cases, a sentinel lymph node biopsy. Learn more in the National Cancer Institute’s skin cancer overview.

Treatment Options That Work

For basal and squamous cell carcinomas (non-melanoma)

Excisional surgery: The tumor and a margin of normal skin are removed; highly effective.
Mohs micrographic surgery: Tissue is removed and examined layer by layer until clear, maximizing cure rates while sparing healthy skin—ideal for the face and other critical areas. Learn more from the AAD.
Curettage and electrodesiccation (ED&C): Scraping and cauterizing superficial tumors; often used for small BCCs.
Topical therapies: Prescription creams like 5-fluorouracil or imiquimod for certain superficial lesions.
Radiation therapy: Considered when surgery isn’t feasible or for select cases.

For melanoma

Wide local excision: Standard for early-stage melanoma, removing the tumor with an appropriate margin.
Sentinel lymph node biopsy: Helps stage intermediate-thickness melanomas.
Immunotherapy: Checkpoint inhibitors (e.g., anti–PD-1, anti–CTLA-4) boost your immune system’s ability to attack cancer; used for advanced or high-risk disease. See the NCI melanoma treatment page.
Targeted therapy: For tumors with BRAF mutations, combinations like BRAF + MEK inhibitors can shrink tumors and delay progression.
Clinical trials: Offer access to cutting-edge therapies—ask your oncologist if you qualify.

Most skin cancers are curable, especially when found early. Your care team will tailor treatment to the cancer type, size, location, and your overall health. Discuss benefits, side effects, recovery time, and cosmetic outcomes—particularly for facial lesions.

Prevention That Actually Works

The good news: Much of skin cancer risk is preventable. These habits offer the biggest payoff:

Use broad-spectrum SPF 30+ sunscreen daily: Apply 15 minutes before sun and reapply every 2 hours (or after swimming/sweating). The FDA explains what “broad spectrum” protects against here: sunscreen basics.
Cover up: Wear UPF-rated clothing, a wide-brim hat, and UV-blocking sunglasses.
Seek shade from 10 a.m. to 4 p.m.: Plan your day using the UV Index; higher numbers mean stronger radiation.
Skip tanning beds: Indoor tanning emits concentrated UV radiation and raises melanoma risk. See the WHO guidance on UV radiation.
Know your meds: Some antibiotics, acne meds, and diuretics cause sun sensitivity—ask your pharmacist or clinician.
Get vitamin D safely: Prefer diet and supplements over intentional sun; see the NIH vitamin D fact sheet.
Do monthly skin checks: Use a mirror or partner to scan scalp, back, and soles. Follow the AAD’s step-by-step guide: how to check your skin.
Book annual professional exams: High-risk individuals (fair skin, many moles, family history, heavy sun exposure) may need more frequent visits—your dermatologist can advise.

How to Do a Fast, Effective Self-Check

Good lighting and a plan make all the difference. After a shower, stand in front of a mirror and scan from scalp to toes. Use a hand mirror for the back and a phone camera to document anything new.

Face and scalp: Part hair in sections; check ears and neck.
Torso and back: Lift arms to view sides; use a mirror for your back.
Arms and hands: Check forearms, palms, and under nails.
Legs and feet: Inspect between toes, soles, and toenails.

Photograph suspicious spots next to a ruler or coin to track changes. If a spot looks concerning for more than a couple of weeks—or matches ABCDE/ugly-duckling signs—schedule a professional exam.

Key takeaways

Learn the signs of skin cancer: ABCDEs, ugly duckling, and non-healing sores.
Act early: New, changing, or unusual spots should be checked promptly.
Treatments are effective, especially when cancers are caught early.
Prevention pays off: Sunscreen, shade, clothing, and smart habits greatly lower risk.

If you’re unsure about a spot, err on the side of caution and see a dermatologist. Quick action today can prevent bigger problems tomorrow.