Skin cancer is the most common type of cancer in the United States. It develops when skin cells grow in an uncontrolled way. These cells may form a tumor, or simply spread across the skin’s surface. In many cases, skin cancer is caused by too much exposure to ultraviolet (UV) rays from the sun or tanning beds. Although it can be serious, most skin cancers can be treated successfully if found early.
Your skin is your body’s largest organ. It protects you from heat, injury, and infection. But it can also be affected by the environment and harmful rays. Over time, the skin can change, and new or unusual spots may appear. While not every change is dangerous, some may be signs of skin cancer.
Knowing how to spot the early signs, understanding what causes it, and seeking the right treatment can make a big difference. This article explains what skin cancer is, its causes and types, common symptoms, and how it’s diagnosed and treated.
What Is Skin Cancer?
Skin cancer begins when skin cells grow out of control. Normally, new skin cells form as old ones die off. But with cancer, the process goes wrong. The cells grow quickly and may form a mass or spread to other parts of the body.
Skin cancer usually starts in areas that are often exposed to sunlight, like the face, neck, arms, and hands. But it can also appear on areas that are rarely exposed, such as the soles of your feet or under your nails. That’s why it’s important to check your whole body regularly.
Some types of skin cancer grow slowly and are easy to treat, while others can spread quickly and become life-threatening if not caught early.
What Causes It and Which Types Are Most Common
The most common cause of skin cancer is exposure to ultraviolet (UV) radiation, which comes from the sun and from tanning beds. UV rays can damage the DNA in your skin cells, and over time, this damage can build up and cause cancer. People who spend a lot of time in the sun, live in sunny climates, or have frequent sunburns have a higher risk. Using tanning beds also increases your risk.
Other factors that may raise your risk include having fair skin, light-colored eyes, or red or blond hair. People with a history of skin cancer in the family or a weakened immune system are also at greater risk.
There are three main types of skin cancer:
Basal cell carcinoma (BCC) is the most common type. It usually appears as a small, shiny bump or patch that may bleed or develop a crust. It rarely spreads but can damage nearby tissue.
Squamous cell carcinoma (SCC) is the second most common type. It often looks like a red, scaly patch, sore, or growth that may crust or bleed. It can spread if left untreated.
Melanoma is the most serious form. It develops in the cells that give skin its color (melanocytes). Melanoma can spread quickly to other parts of the body. It may look like a new mole or a change in an existing mole.
There are also rarer types of skin cancer, such as Merkel cell carcinoma and some types that start in sweat glands or other skin structures, but the three types above make up the vast majority of cases.
What Symptoms to Look Out For
The symptoms of skin cancer vary depending on the type. But any change in your skin that doesn’t go away should be checked by a doctor. Common signs include:
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A new growth or bump on the skin
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A sore that doesn’t heal
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A mole that changes in size, shape, or color
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A spot that looks different from others on your skin
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Itching, bleeding, or pain in a mole or spot
Melanoma is often found by noticing changes in a mole. The ABCDE rule can help you remember the warning signs:
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A for Asymmetry: one half looks different from the other
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B for Border: edges are uneven or irregular
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C for Color: there are several colors or shades
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D for Diameter: larger than 6 mm (about the size of a pencil eraser)
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E for Evolving: the mole is changing over time
It’s important to regularly check your skin from head to toe, including hard-to-see areas like your back, scalp, and the bottoms of your feet. Ask someone to help if needed.
How It’s Diagnosed
If you notice a suspicious spot, your doctor will examine it closely. They may ask how long it’s been there and whether it has changed. In many cases, the next step is a skin biopsy, where a small sample of the skin is removed and sent to a lab. This is the only way to confirm whether it’s cancer.
If the biopsy confirms cancer, your doctor may perform additional tests to see how deep the cancer goes and whether it has spread. This may include imaging scans or checking nearby lymph nodes.
Early diagnosis is key. When caught early, most skin cancers can be removed completely with little or no scarring. Delayed treatment may lead to more serious problems and the need for more complex care.
Treatment Options
Treatment depends on the type of skin cancer, how big it is, and where it’s located. In most cases, skin cancer is treated with minor surgery to remove the cancerous tissue.
Surgical removal may involve cutting out the cancer and a small amount of surrounding tissue. For small or surface-level cancers, this can often be done in a doctor’s office.
Mohs surgery is a special technique used mostly on the face or in areas where saving healthy skin is important. The doctor removes the cancer layer by layer, examining each layer under a microscope until no cancer remains.
Cryotherapy uses liquid nitrogen to freeze and destroy cancer cells. It’s often used for very early skin cancers or precancerous spots.
Radiation therapy may be used if surgery isn’t possible, or to treat areas where surgery might cause scarring.
Topical medications may be used for certain early skin cancers. These creams help the immune system fight off the abnormal cells.
For advanced cases, especially melanoma, treatment may include immunotherapy, targeted therapy, or chemotherapy, depending on how far the cancer has spread.
