When should I call the doctor?

Though age spots aren't dangerous and don't require medical treatment, some changes to your skin can spell trouble. Have your doctor or dermatologist check out any new dark spots, especially ones that have quickly changed or grown, have an uneven border, or have combined different colors. These could be signs of melanoma, a dangerous type of skin cancer [source: Mayo Clinic].

What causes age spots?

Are age spots caused by aging? Aging itself is a factor, but variables such as ultraviolet radiation exposure and genetics also play a part [source: Mayo Clinic].

Although adults older than age 40 are more likely to have age spots than younger folks, it's usually sun exposure over many years, rather than aging itself, that's the primary cause [source: Medline Plus]. If you've spent a lot of time in the sun, your skin has probably sustained some damage from ultraviolet rays. Though a suntan might look healthy, it's not -- too much sun is harmful to the skin. The skin contains melanocytes, the cells that produce the pigment melanin, which helps protect the skin from the sun. Melanin gives skin its color, but extra melanin can result in age spots.

Sometimes as people get older, their bodies produce extra melanin as a result of the aging process. Generally, though, excess melanin is caused by frequent exposure to the sun's UV rays. That's why areas of your body that get the most sun, such as the face, hands and neck, are most often the location of age spots. Intense sun exposure and sunburn are known risk factors for developing age spots. Keep in mind that tanning beds are not a safer alternative, because they also generate harmful UV rays and a similar effect on your body as the sun does [source: Boyles].

Genetics also play a part. Some people are genetically inclined to develop age spots.

Also, if you've inherited fair skin, you are more prone to developing age spots than people with darker skin because your body is used to producing melanin to protect you [source: Mayo Clinic].

What steps can you take now to prevent age spots in the future? Read on to find out.