Healthcare professionals advise people to check for symptoms of skin cancer regularly throughout the year. Early detection improves the outlook of each type of skin cancer.

Skin cancer is the most common cancer in the United States. Melanoma is the most dangerous type, but it is less common than other forms of skin cancer.

This article will describe the symptoms of the most common types of skin cancer and explain how to check the skin for them. It will also cover prevention, causes, and risk factors, as well as diagnosis and treatment.

There are different forms of skin cancer, and the most common are:

  • basal cell carcinoma
  • squamous cell carcinoma
  • melanoma

Melanoma is the type most likely to develop in a mole.

The Skin Cancer Foundation says that everyone should examine their whole body, from head to toe, once per month. In doing so, they should take note of:

  • any new moles or growths
  • moles or growths that have grown
  • moles or growths that have changed significantly in another way
  • lesions that change, itch, spontaneously bleed, or do not heal

The most common symptom of skin cancer is an unusual pink or brown spot, patch, or mole.

Enlarged lymph nodes can also signal skin cancer. Lymph nodes are collections of lymphatic tissue through which immune cells pass and where some immune cells reside. Many lymph nodes are in the neck, groin, and underarms.

Basal and squamous cell skin cancers are more common and not as dangerous as melanoma. They can develop anywhere, but they are most likely to form on the face, head, or neck.

A basal cell carcinoma may:

  • be a flat, firm area of skin, similar to a scar
  • be a raised, sometimes itchy patch of skin
  • be pale, reddish, yellow, or pink on white skin
  • be the same color as the skin or darker on black or brown skin
  • take the form of small, shiny, pearly bumps with blue, brown, or black areas
  • be growths that have raised edges and a lower center plus abnormal blood vessels that spread from the growth like the spokes of a wheel
  • take the form of open sores that ooze or crust and either do not heal or heal and return

A squamous cell carcinoma may:

  • be a rough or scaly red patch that may crust or bleed
  • be a raised growth or lump, sometimes with a lower center
  • take the form of open sores that ooze or crust and either do not heal or heal and return
  • be a growth that looks like a wart

Not all skin cancers look alike. The American Cancer Society recommends that people contact a doctor if they notice:

  • a mark that does not look like others on their body
  • a sore that does not heal
  • changes in skin color or new swelling outside the border of a mole
  • itching, pain, or tenderness in a mole
  • oozing, scaliness, or bleeding in a mole
  • a dark streak around a nail

Symptoms on black and brown skin

On dark skin, it may be easier to feel a lesion than see it. People with black skin may be more likely to find a lesion on a part of the body that has little exposure to the sun, according to the American Academy of Dermatology.

Skin cancer can affect people with any skin color, but those with brown or black skin are more likely to receive a diagnosis at a later stage. This may be due to a lack of awareness of how skin cancer appears on skin colors other than white.

Anyone who notices an unusual change in their skin should seek medical advice as soon as possible.

Learn more about skin cancer in black skin here.

The medical community has developed two ways to spot the early symptoms of melanoma. This is the most dangerous type of skin cancer.

A person can use the ABCDE method or the ugly duckling method.

The ABCDE method

Brown spots, marks, and moles are usually harmless. However, the first symptom of melanoma can occur in what doctors call an atypical mole, or dysplastic nevi.

To spot an atypical mole, check for the following:

  • A: Asymmetry. If the two halves of a mole do not match, this can be an early indication of melanoma.
  • B: Border. The edges of a harmless mole are even and smooth. If a mole has uneven edges, it can be an early symptom of melanoma. The mole’s border may also be scalloped or notched.
  • C: Color. Harmless moles are a single shade, usually of brown. Melanoma can cause differentiations in shade, from tan, brown, or black to red, blue, or white. On dark skin, the lesion may be darker, or color changes may be less pronounced.
  • D: Diameter. Harmless moles tend to be smaller than dangerous ones. Dangerous moles are usually around one-quarter of an inch (6 millimeters) across.
  • E: Evolving. If a mole starts to change, or evolve, this can be a warning sign. Changes may involve shape, color, or elevation from the skin. Alternatively, a mole may start to bleed, itch, or crust.

It is worth noting that 70–80% of melanomas occur in a new lesion rather than from an existing mole.

The ugly duckling method

The ugly duckling method works on the premise that a person’s moles tend to resemble one another. If one mole stands out in any way, it may indicate skin cancer.

Of course, not all moles and growths are cancerous. However, if a person notices any of the above characteristics, they should speak with a doctor.

First, a doctor will examine a person’s skin and take their medical history. They will usually ask the person when the mark first appeared, if its appearance has changed, if it is ever painful or itchy, and if it bleeds.

The doctor will also ask about the person’s family history and any other risk factors, such as lifetime sun exposure.

They may also check the rest of the body for other atypical moles and spots. Finally, they may feel the lymph nodes to determine whether or not they are enlarged.

The doctor may then refer a person to a skin doctor, or dermatologist. They may examine the mark with a dermatoscope, which is a handheld magnifying device, and take a small sample of skin, or a biopsy, and send it to a laboratory to check for signs of cancer.

Researchers do not know why certain cells become cancerous. However, they have identified some risk factors for skin cancer.

The most important risk factor for melanoma is exposure to UV rays. These damage the skin cells’ DNA, which controls how the cells grow, divide, and stay alive.

Most UV rays come from sunlight, but they also come from tanning beds.

Some other risk factors for skin cancer include:

  • A lot of moles: A person with more than 100 moles is more likely to develop melanoma.
  • Fair skin, light hair, and freckles: The risk of developing melanoma is higher among people with fair skin. Those who burn easily have an increased risk.
  • Family history: Around 10% of people with the condition have a family history of it.
  • Personal history: Melanoma is likelier to form in a person who has already had it. People who have had basal cell or squamous cell cancers also have an increased risk of developing melanoma.

The best way to reduce the risk of skin cancer is to limit one’s exposure to UV rays. A person can do this by using sunscreen, seeking shade, and covering up when outdoors.

People should also avoid tanning beds and sunlamps to reduce their risk of skin cancer.

It can be easy to mistake benign growths for skin cancer.

The following skin conditions have similar symptoms to skin cancer:

  • Seborrheic keratosis: These are brown, black, or tan growths that appear in older adults.
  • Cherry angioma or hemangioma: These are small growths, made up of blood vessels, that are typically red but may rupture and turn brown or black.
  • Freckles: These are flat, darker areas of skin that appear after the skin has exposure to UV light.
  • Dermatofibroma: These are small, firm, round bumps that form under the skin and may change color over time.
  • Skin tags: These are soft, harmless growths.

Doctors usually remove basal cell and squamous cell cancers with minor surgery.

Radiation therapy is an alternative treatment when a person cannot undergo surgery. A doctor may also recommend this treatment when the cancer is in a place that would make surgery difficult, such as on the eyelids, nose, or ears.

For melanoma, the best treatment will depend on the stage and location of the cancer. If a doctor diagnoses melanoma early, they can usually remove it with minor surgery.

In some cases, doctors may suggest other types of surgery or therapy.

Healthcare professionals advise people to check for symptoms of skin cancer regularly.

The most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma, and melanoma. Receiving a diagnosis early will improve the outlook, regardless of the type.

If a mole or mark has undefined or uneven edges, has multiple colors, or is atypical in any way, it can indicate skin cancer, as can the appearance of sores that do not heal. Anyone who has concerns about marks, moles, or lesions on their skin should speak with a doctor.

Exposure to UV light is the most significant risk factor for skin cancer. The best way to prevent this condition is to stay safe in the sun.