Many people refer to a mole as any dark spot or irregularity in the skin. Doctors use different terms. But the following types of skin marks such as these are not treated the same way moles are and are not discussed here:
Abnormal formations of blood vessels (hemangiomas)
Keratoses (benign or precancerous spots, which appear after about age 30 years)
What causes Moles?
Some people are born with moles. Other moles appear later in life.
Sun exposure seems to play a role in the development of moles and may even play a role in the development of atypical, or dysplastic, moles.
The role of heredity cannot be overemphasized. Many families have a type of mole known as dysplastic (atypical), which can be associated with a higher frequency of melanoma.