All About Moles

Moles, scientifically known as melanocytic naevi, are small spots on the skin that mostly have a brownish color, although they can also appear as blue or black. Moles are made up of cells called melanocytes, which are the cells that are responsible for your skin color. Moles can occur anywhere on the skin, and most people have only a few of them; usually not more than 40.

How Moles Occur

Moles can be present at birth, but most of them most commonly appear during puberty and stop appearing by the age of 20. Scientists say that the moles are caused when melanin is overproduced in skin cells' clumps. However, the cause of the overproduction of melanin is still unknown.

Moles have a smooth edge and are usually oval or circular. Moles usually start out flat, but may become raised over time and become rough. Hair may also be seen on some moles. Over time moles change in their appearance and number and some may fade without your knowledge. Changes in hormones may also alter how moles appear. For instance:

  • during pregnancy they may darken a bit,
  • during the teenage years their number may increase, and
  • between the ages of 40 to 50 onwards they may disappear altogether.

Types of Moles

There are many variants of melanocytic naevi. The most common ones are:

  • Junctional moles: Usually, this type of mole is brown, flat and round.
  • Compound moles: These moles are characterized by a light brown color, a raised surface     and usually the presence of hair.
  • Dermal moles: These moles are usually pale, raised above the skin and hairy in some instances.

There are also some rare types of melanocytic naevi. They include:

  • Atypical or dysplastic naevi: Also referred to as Clark naevi, they have an unusual appearance and are slightly bigger than normal moles. They occur in a variety of colors and they may be flat as well as bumpy.
  • Halo naevi: These moles are usually surrounded by a ring, which is white in color, that signifies the loss of skin color.
  • Blue naevi: These moles are dark blue in color.

Signs of Healthy and Unhealthy Moles

Most moles are not harmful and don't need to be tested by medical professionals. However, depending on their appearance and where they are located, some moles may need medical attention. This is mainly because some moles undergo a change resulting in malignant melanoma, which is a type of skin cancer. The chance of this happening is about one in a million, making it the least common strain of skin cancer. However, it is the most hazardous of the skin cancer strains. Research has linked malignant melanoma in adults to extreme childhood sunburns.

To check and do away with any doubts of having malignant melanoma, you need to have a medical check-up the moment you realize a change in the moles. In particular, note any change in:

  • Size – Your mole spreading and broadening is a sign of a potentially cancerous mole.
  • Border – If your mole has a weird, irregular outline it may be cancerous.
  • Color - Inspect your moles for any color changes. Especially note if  different color shades  appear on  a   single mole.
  • Surface appearance of the mole - This could be scaling, oozing, bleeding or crusting of the mole.


Since most moles are not harmful, there is no need to be alarmed with moles that stay consistent in size, shape and color. However, the slightest abnormality should be considered as impending danger and treated as so. Look out for the above signs in regards to your moles, and get to the dermatologist right away to have them checked out. If your moles are cancerous, or raise suspicion with your dermatologist, you will probably need to have a mole removal procedure.