Moles are usually brownish, but some may be much darker, while others are skin-colored. They can be rough, flat, raised, and have hair growing out of them. They are generally round or oval, and have a smooth edge.Moles can change in appearance and amount. Sometimes they eventually fade away or drop off. Some moles respond to changes in hormone levels, as may occur during pregnancy, adolescence, and older age.

During teen years they usually grow in number, they also get darker during pregnancy and gradually fade away as people age. The majority of moles appear during the first 20-30 years of a person's life, however, some may be present when the baby is born. Congenital melanocytic nevi are present at birth, any moles appearing after birth are melanocytic nevi. Dark skinned people generally have fewer moles than those with fair skin. Moles are small lesions in the skin. They are a collection of melanocytes. Melanocytes are melanin-producing cells. Melanin is a pigment which gives skin its color.