Most moles will gradually change over time. They may get bigger, grow a hair, become more raised, get lighter in color, or fade away. Many people develop new moles until about age 40.

Melanoma, a serious type of skin cancer, often begins as a change in a mole or other skin growth. These early signs are described in the ABCDE system:

• Asymmetry. One half doesn't match the other half.
• Border irregularity. The edges are ragged, notched, or blurred.
• Color. The color is not uniform. Shades of tan, brown, and black are present. Dashes of red, white, and blue make the mole look blotchy.
• Diameter. The mole is larger than 6 mm (0.2 in.) across (about the size of a pencil eraser). Any growth of a mole should be of concern.
• Evolution. There is a change in the size, shape, symptoms (such as itching or tenderness), surface (especially bleeding), or color.

Early detection of skin cancer includes regular skin self-exams in which you look at your skin and note any changes in skin growths. A skin self-exam may help identify suspicious skin growths and lead to early treatment. Perform a skin self-exam once a month.

• Check your skin, scalp, and skin growths for any changes in color, shape, size, or appearance.
• Check to see if any area of your skin or scalp has not healed after an injury.
• If you notice a suspicious skin growth, have your doctor look at it. Most skin growths can be removed, which will keep them from growing and damaging the surrounding skin or other deeper tissues or spreading to other areas of the body.

Because skin cancer develops in moles and colored skin spots, it is important to be safe and have any changes checked by your doctor. Early detection and treatment of skin cancer can prevent problems.