Benign moles are noncancerous skin growths. They are typically symmetrical with a rounded shape and a smooth edge.

A mole is a small collection of skin cells. It’s also known as a nevus (the plural is “nevi”). Most people have 10–40 moles on their body, and these moles are typically benign (noncancerous). Moles that are present from birth are called congenital nevi, while moles that appear throughout your life are called acquired moles.

Moles come in various sizes, textures, and colors. Irregularly shaped moles with more colors have a greater chance of being cancerous. It’s important to consult a doctor if a mole’s appearance changes, if it becomes painful, or if you’re not sure whether it’s benign.

Benign moles typically:

  • are round or oval-shaped
  • are smaller than 5 millimeters wide
  • are the same color throughout
  • have distinct, smooth edges

Benign moles can be either flat or raised and can have hairs growing out of them.

Moles are caused by irregular skin growth. Special cells that contain melanin are responsible for the darker coloring of moles.

About 1 in 100 babies are born with a mole. But these moles can be much larger than those acquired later in life. Genetic mutations in the womb are believed to play a role in the formation of congenital moles.

Most people develop moles until they are about 40 years old. Exposure to the sun and UV rays is thought to be a cause of many acquired moles. Genetics may also affect the number of moles you develop.

There is a chance that benign moles may become cancerous over time. Atypical moles known as dysplastic nevi are more likely to become cancerous. About 1 in 10 Americans have at least one dysplastic nevus on their body.

While it is rare for a benign mole, including a dysplastic nevus, to become melanoma (a type of skin cancer), it is possible. UV exposure and a family history of melanoma can increase your chances of developing skin cancer.

Removal of benign moles also has some risks, including:

  • scarring
  • infection
  • wound separation
  • recurrence of the mole

To determine whether your mole is benign, a doctor will visually examine it and compare it to the appearance of other benign moles. Depending on what they see, they may perform a skin biopsy. This is the only way to definitively find out whether a mole is cancerous.

During a skin biopsy, the doctor will remove a portion of skin that looks atypical and send it to a lab for testing. The procedure usually takes only a few moments, but you may have to wait several days or weeks for the results.

Moles typically do not need to be treated unless they are cancerous. If your doctor is concerned that a mole is cancerous, they may recommend surgically removing it.

Should benign moles be removed?

Most benign moles do not need to be removed. The likelihood that a benign mole will become cancerous is small. If the mole’s location or size is undesirable, you can talk with your doctor about having it removed for cosmetic reasons, but insurance may not cover the procedure.

You should contact a doctor if you:

  • notice that a mole has changed in color, shape, or size
  • have a mole that has become itchy, crusty, or inflamed or is bleeding
  • develop an unusual mark on your skin that does not go away after several weeks
  • are not sure whether a mole is benign
  • want to remove a mole

Here are answers to some of the most commonly asked questions about benign moles:

What is a benign mole?

A benign mole is a small, colored, noncancerous growth on your skin.

Can benign moles grow?

Yes, benign moles can grow, especially as a child ages. Congenital moles will grow proportionally to your body. If a mole is growing unevenly, it’s important to mention this to your or your child’s doctor.

Can a normal mole be two colors?

Yes, benign moles can have two colors. But a mole with additional colors is more likely to be cancerous.

Can a mole look like melanoma but be benign?

Yes, atypical moles called dysplastic nevi can look like melanoma even though they are benign. The only way to find out for sure whether a mole is benign or cancerous is to perform a biopsy, which involves taking a sample of skin cells.

Can a benign mole become malignant?

A benign mole can turn into melanoma, but this is rare.

Can benign moles disappear?

Yes, it’s common for moles to fade or disappear as you age.

Moles are common skin growths, and most are benign (noncancerous). Benign moles tend to be round or oval-shaped and have smooth edges. Benign moles typically do not need treatment, but it’s important to monitor any moles you have for signs of cancer.

You should contact a doctor if you have a mole that changes in shape or color or becomes painful. If your doctor is concerned that a mole may be cancerous, they can perform a biopsy and might recommend surgically removing it.