Keeping an eye on your moles, especially if you spend a lot of time in the sun, is wise. Below is a basic explanation of moles and five warning signs that warrant a trip to a dermatologist.

What is a Mole?

A mole is created by a concentration of melanocytes, cells that have the pigment melanin and that determine skin color. The cells grow in a cluster rather than being distributed evenly throughout the skin. The moles tend to darken when exposed to sunlight. They may also darken during hormonal changes in the body, such as during puberty or pregnancy. 

Two Basic Types of Moles

Congenital moles appear at birth, sometimes called birthmarks. Freckles are another type of mole, usually smaller and lighter that the typical solitary mole. Congenital moles, and most freckles, are usually harmless but should be checked if any changes occur.

Dysplastic moles are typically larger than congenital moles, more than a pencil eraser in diameter, and sometimes have an irregular shape. They don't have the even color of the congenital moles, but have light and dark areas. These moles form after birth and may start out benign but are more apt to become cancerous. They bear extra watching.

Five Warning Signs of Melanoma, or Skin Cancer

When moles start displaying any of these five warning signs, it's time to see your doctor or someone at a place like TrueSkin Dermatology & Surgery, Inc.

• Benign moles are usually symmetrical. If you divide this type of mole in half, both halves will match. Exceptions do exist. A symmetrical mole that becomes asymmetrical, having unmatched sides, should be checked. 
• The borders of benign moles are usually smooth and even. Malignant moles tend to have uneven edges, often with lace-like borders.
• Most benign moles are one even shade of brown. If you have a mole that's been one shade of brown for years and different shades of brown appear, you might want to get it looked at. Some melanomas also turn red, blue or white, or any variations of those colors. 
• Size also matters. Benign moles are smaller, usually less than 1/4 inch wide. Anything larger than that, especially if other symptoms occur, should be seen. Some melanomas start out small but then grow quickly.
• A mole that is changing from benign to cancerous is called an evolving mole. It will show one or more of the symptoms above, or the mole could become itchy, bleed periodically or develop a crust-like coating.  

Many of these mole changes may be avoided or minimized by making a good sunscreen your best friend.