Moles are medically known as nevi and they are basically a cluster of pigmented cells that are seen on the skin as black or brown spots. There are different types of moles. While most of the time the moles are harmless, there are a few which could be cosmetically unappealing or very rarely may become cancerous. They can appear on any part of the body and by the time you reach adulthood, you could have around 10-40 moles, as per a study. With age, some of the moles disappear and few others change their color or may grow in size.
A mole is formed when a group of cells called melanocytes come together and grow in a cluster at a particular spot on the body. They may be flat or protruding. The different types are congenital moles (formed during birth) and acquired moles (which appear later in life). However, if the moles start getting painful, start itching or bleeding, increase rapidly in size, or if there is any asymmetry then it is advisable to consult a dermatologist.