What skin cancer looks like and when to see a doctor

Skin cancer usually appears as a new spot on your skin or a change to a spot you already have. The most common sign is a spot that looks different from your other moles or freckles — either darker, larger, oddly shaped, or with an uneven color. Some skin cancers itch, bleed, or don't heal. If you notice any of these changes, schedule an appointment with your primary care doctor or a dermatologist (a doctor who specializes in skin). You do not need to wait or assume it will go away on its own.

The key is that skin cancer caught early is far more treatable than skin cancer found later. This means you should not ignore a spot just because it doesn't hurt or because you've had it for a while. A doctor can examine it in person, and if there is any doubt, they can remove a small sample to test it in a lab.

Key Takeaways

  • The ABCDE rule helps you spot changes: Asymmetry (one half doesn't match the other), Border irregularity, Color variation, Diameter larger than a pencil eraser, and Evolving (changing in size, shape, or color).
  • Any new spot, or any change to an existing mole or freckle, warrants a doctor's visit — you cannot tell from looking whether it is cancer.
  • Skin cancer can appear anywhere on your body, including areas that don't get much sun, so check your scalp, between your toes, and your palms.
  • A dermatologist can examine a suspicious spot in minutes and take a biopsy (a tiny tissue sample) if needed to confirm what it is.

The ABCDE rule for spotting melanoma

Asymmetry means one half of the spot does not look like the other half. Draw an imaginary line down the middle — if the two sides are different shapes or colors, that is a warning sign. Normal moles are usually symmetrical.

Border irregularity means the edge is jagged, scalloped, or blurry instead of clean and even. Color variation means the spot has more than one shade — brown and black together, or brown and red, or tan and black. A normal mole is usually one solid color.

Diameter larger than a pencil eraser (about 6 millimeters) is a flag, though not all skin cancers are this large. Evolving means the spot is changing — getting bigger, changing shape, or changing color over weeks or months. Any change at all is worth mentioning to a doctor.

The ABCDE rule is most useful for melanoma, the most serious type of skin cancer. Other types, like basal cell carcinoma and squamous cell carcinoma, may not follow this pattern, so do not assume a spot is safe just because it does not fit all five criteria.

Other warning signs besides the ABCDE rule

A spot that bleeds, oozes, or does not heal is a red flag. So is a spot that itches or feels tender when you touch it. A sore that scabs over and then opens again, over and over, should be checked. A shiny bump or a flat, scaly patch that grows slowly over time also warrants a doctor's visit.

Skin cancer can look like a wart, a scar, or a patch of dry skin. It can be skin-colored, pink, red, brown, or black. It can appear on your face, your hands, your back, your legs, or anywhere else — including your scalp, your ears, between your toes, or on your palms. Do not assume a spot is harmless because of where it is or what color it is.

Where to check and how often

Once a month, spend a few minutes looking at your whole body in a mirror. Start with your face, ears, and scalp (use a comb or your fingers to part your hair). Check your neck, chest, and shoulders. Look at your arms, the backs of your hands, and between your fingers. Examine your torso, your legs, the tops and bottoms of your feet, and between your toes. Do not forget your back — use a hand mirror or ask someone to help you look.

Write down any spots you find, or take a photo of them. This way, if you see a change over the next month or two, you will notice it. If you have a lot of moles or freckles, or if you have a family history of skin cancer, ask your doctor how often you should have a professional skin check. Some people benefit from a full-body exam by a dermatologist once a year.

When to call your doctor versus when to go to urgent care

If you notice a new spot or a change to an existing one, call your primary care doctor or a dermatologist and describe what you see. Most offices can fit you in within one to two weeks. You do not need to go to urgent care or the emergency room unless the spot is bleeding heavily, infected (warm, red, swollen, or draining pus), or causing severe pain.

If you cannot reach your regular doctor quickly and you are worried, you can call a dermatology office directly — many practices reserve same-day or next-day slots for new spots that concern patients. Some primary care doctors can refer you to a dermatologist the same day you call. If cost is a concern, ask whether the office offers a sliding scale or payment plan.

What happens at a skin cancer check

A doctor will look at the spot with their eyes, and often with a magnifying tool called a dermatoscope. They will ask how long you have had it, whether it has changed, and whether it itches or bleeds. If the doctor thinks it might be cancer, they will numb the area with a local anesthetic and remove a small sample of skin — this is called a biopsy. You will feel pressure but not pain.

The sample goes to a lab, and you usually get results within one to two weeks. If the biopsy shows cancer, the doctor will talk to you about next steps, which may include removing more skin around the spot, watching it over time, or referring you to an oncologist (a cancer specialist). If the biopsy is not cancer, the doctor will tell you what it is and whether you need any treatment.

Risk factors that mean you should check more often

You are at higher risk for skin cancer if you have fair skin, red or blonde hair, blue or green eyes, or a family history of skin cancer. You are also at higher risk if you have had a lot of sun exposure over your lifetime, if you have had a severe sunburn, or if you use or have used a tanning bed. If any of these apply to you, check your skin monthly and ask your doctor about annual skin exams.

People with darker skin can also get skin cancer, though it is less common. Skin cancer in people with darker skin is often found later because it is less expected, so it is important to check your skin regardless of your skin tone and to mention any changes to your doctor.

Frequently Asked Questions

Can a dermatologist tell if a spot is cancer just by looking at it?

A dermatologist can often tell, but the only way to be certain is a biopsy. Some spots look suspicious but turn out to be harmless, and some look innocent but are cancer. This is why a biopsy is the standard when there is any doubt.

What if I have a spot that fits the ABCDE rule but my doctor says it is not cancer?

Your doctor may recommend a biopsy to be sure, or they may say the spot is a benign (non-cancerous) mole that just happens to have some of these features. If you remain concerned, you can ask for a second opinion from a dermatologist or request a biopsy for peace of mind.

Do I need to remove a mole if it is not cancer?

No. A benign mole does not need to be removed unless it bothers you for cosmetic reasons, gets in the way of shaving, or changes in a way that worries you. If you want it removed, a dermatologist can do this in the office.

Is it true that checking your skin too often causes anxiety?

Monthly checks are routine and take only a few minutes. If you find yourself obsessing or feeling very anxious, talk to your doctor. They can help you understand what is normal and what warrants concern, which often eases worry.

What should I do if I find a spot that looks like skin cancer?

Call your doctor or a dermatology office and describe what you see. Do not wait to see if it goes away. Most offices can see you within one to two weeks, and early detection makes a real difference in treatment options.