Skin cancer happens when something changes how your skin cells grow, like exposure to ultraviolet light. Symptoms include new bumps or patches on your skin, or changes in the size, shape or color of skin growths. Most skin cancer is treatable if it’s caught early. Treatments include Mohs surgery, cryotherapy, chemotherapy and radiation.
Skin cancer is a disease that involves the growth of abnormal cells in your skin tissues. Normally, as skin cells grow old and die, new cells form to replace them. When this process doesn’t work as it should — like after exposure to ultraviolet (UV) light from the sun — cells grow more quickly. These cells may be noncancerous (benign), which don’t spread or cause harm. Or they may be cancerous.
Skin cancer can spread to nearby tissue or other areas in your body if it’s not caught early. Fortunately, if skin cancer is identified and treated in early stages, most are cured. So, it’s important to talk with your healthcare provider if you think you have any signs of skin cancer.
There are three main types of skin cancer:
Other types of skin cancer include:
Skin cancer is the most common cancer diagnosed in the U.S. In fact, about 1 in 5 people develop skin cancer at some point in their life.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
The most common warning sign of skin cancer is a change on your skin — typically a new growth or a change in an existing growth or mole. Skin cancer symptoms include:
Skin cancer looks different depending on what type of skin cancer you have. Thinking of the ABCDE rule tells you what signs to watch for:
If you’re worried about a mole or another skin lesion, make an appointment and show it to your healthcare provider. They’ll check your skin and may ask you to see a dermatologist and have the lesion further evaluated.
The main cause of skin cancer is overexposure to sunlight, especially when you have sunburn and blistering. UV rays from the sun damage DNA in your skin, causing abnormal cells to form. These abnormal cells rapidly divide in a disorganized way, forming a mass of cancer cells.
Anyone can get skin cancer, regardless of race or sex. But some groups get it more than others. Before the age of 50, skin cancer is more common in women and people assigned female at birth (AFAB). After 50, though, it’s more common in men and people assigned male at birth (AMAB). And it’s about 30 times more common in non-Hispanic white people than non-Hispanic Black people or people of Asian/Pacific Islander descent. Unfortunately, skin cancer is often diagnosed in later stages for people with darker skin tones. This makes it more difficult to treat.
Although anyone can develop skin cancer, you’re at increased risk if you:
First, a dermatologist may ask you if you’ve noticed changes in any existing moles, freckles or other skin spots, or if you’ve noticed any new skin growths. Next, they’ll examine all of your skin, including your scalp, ears, palms of your hands, soles of your feet, between your toes, around your genitals and between your buttocks.
If your provider suspects skin cancer, they may perform a biopsy. In a biopsy, a sample of tissue is removed and sent to a laboratory where a pathologist examines it under a microscope. Your dermatologist will tell you if your skin lesion is skin cancer, what type you have and discuss treatment options.
Cancer stages tell you how much cancer is in your body. The stages of skin cancer range from stage 0 to stage IV. In general, the higher the number, the more cancer has spread and the harder it is to treat. But the staging for melanoma is different from non-melanoma skin cancers that start in your basal or squamous cells.
Treatment depends on the stage of cancer. Sometimes, a biopsy alone can remove all the cancer tissue if it’s small and limited to the surface of your skin. Other common skin cancer treatments, used alone or in combination, include:
The side effects of skin cancer treatment depend on what treatments your healthcare provider think will work best for you. Chemotherapy for skin cancer can lead to nausea, vomiting, diarrhea and hair loss. Other side effects or complications of skin cancer treatment include:
In most cases, skin cancer can be prevented. The best way to protect yourself is to avoid too much sunlight and sunburns. UV rays from the sun damage your skin, and over time, this may lead to skin cancer.
Ways to protect yourself from skin cancer include:
Nearly all skin cancers can be cured if they’re treated before they have a chance to spread. The earlier skin cancer is found and removed, the better your chance for a full recovery. It’s important to continue following up with your dermatologist to make sure cancer doesn’t come back. If something seems wrong, call your doctor right away.
Most skin cancer deaths are from melanoma. If you’re diagnosed with melanoma:
Make an appointment to see a healthcare provider or dermatologist as soon as you notice:
Your provider will check your skin, take a biopsy (if needed), make a diagnosis and discuss treatment. Also, see a dermatologist annually for a full skin review.
Questions to ask your dermatologist may include:
You may wonder how cancer on the surface of your skin becomes a life-threatening cancer. It seems logical to think you could just scrape off the skin with the cancer cells or even remove the cancerous skin lesion with a minor skin surgery and that’s all that would be needed. These techniques are successfully used if cancer is caught early.
But if skin cancer isn’t caught early, something that’s “just on my skin” can grow and spread beyond the immediate area. Cancer cells can break away and travel through your bloodstream or lymph system. They can settle in other areas of your body and begin to grow and develop into new tumors. This travel and spread is called metastasis.
The type of cancer cell where cancer first started — called primary cancer — determines the type of cancer. For example, if malignant melanoma metastasized to your lungs, the cancer would still be called malignant melanoma. This is how that superficial skin cancer can turn into life-threatening cancer.
Scientists don’t fully know why people with darker skin tones develop cancer in non-sun-exposed areas like the palms of your hands and feet. They think that the sun is less of a factor, though. That said, dermatologists still see plenty of UV sunlight-induced melanomas and squamous cell skin cancer in people with skin tones ranging from fair to very dark.
Most moles aren’t cancerous. Some moles are present at birth. Others develop up to about age 40. Most adults have between 10 and 40 moles.
In rare cases, a mole can turn into melanoma. If you have more than 50 moles, you have an increased chance of developing melanoma.
A note from Cleveland Clinic
Skin cancer can happen to anyone. What may seem like an innocent cosmetic imperfection may not be. Performing regular skin self-checks is important for everyone. But it’s especially important if you have an increased risk of skin cancer.
Your skin is the largest organ in your body. And it needs as much attention as any other health concern. Check your skin every month for any changes in skin spots or any new skin growths. Take steps to protect your skin from the sun. And don’t forget to schedule regular skin checks with your dermatologist.
Last reviewed by a Cleveland Clinic medical professional on 11/19/2021.
Learn more about our editorial process.