If you have discolored or dark patches of skin, you aren't alone. Millions of people experience hyperpigmentation, or too much pigment, in certain areas at some point in their lives. The most common pigment disorders are dark solar lentigo spots, often called sun spots or liver spots, and melasma, otherwise known as "the mask of pregnancy."

The good news is that if you treat your skin properly and make a commitment to avoid the sun and use sunscreen, you can often alleviate pigment problems, says Dr. Jeanine Downie, a dermatologist and spokeswoman for the Skin Pigmentation Knowledge Center.

Here, she answers frequently asked questions about skin pigment disorders:

What's the best way to avoid getting brown spots or sun spots (solar lentigo)?

Stay out of the sun. The name of this skin condition says it all. The term "solar" refers to the sun or its rays, while a lentigo is a benign flat brown spot usually appearing on sun-exposed skin, such as the face or back of the hands. Solar lentigo is a skin condition caused by chronic exposure to the sun or to ultraviolet radiation. Often called "sun," "age" or "liver" spots, solar lentigines appear like large brown freckles.

My grandmother says the sun causes liver spots. Are sun spots and liver spots the same?

Yes. Sun spots are sometimes referred to as liver spots because of their shape and color. They are often flat or oval lesions with slightly irregular borders. They are in no way a result of liver disease.

What does melasma look like?

Melasma, also called the mask of pregnancy, is characterized by dark spots or blotches on the face, forehead and neck, says Dr. Downie. You'll often find it in a symmetrical pattern.

I'm planning to get pregnant. Will I get melasma? What causes it?

Melasma is caused by a combination of sun exposure and hormones. When these factors are combined in some women, melanin production is increased in certain areas and melanin is then deposited into the top layers of the skin.

Unfortunately, you can't tell in advance if you will get melasma, although according to the American Academy of Dermatology, if someone in your family had it, you have a 30 percent chance of having it. In general, melasma occurs in 50 to 70 percent of pregnant women and 5 to 34 percent of women taking birth control pills. The condition usually strikes women between the ages of 20 and 39.

How can I avoid melasma or other pigment problems?

You may not be able to avoid hyperpigmentation, but you can manage it. We recommend vigilant sun avoidance and rigorous use of sunscreens.
Patients seeking treatment can go to a dermatologist for cryotherapy (freezing with liquid nitrogen), laser therapy, bleaching creams and chemical peels.

The main mode of treatment is the use of topical depigmenting, or "bleaching" agents, often in conjunction with a retinoid or a topical low-potency steroid. Hydroquinone is the most common depigmenting agent, used in a four percent concentration by prescription. Some products with a two percent concentration are available over the counter, but these have a limited effect.

Products containing tretinoin ingredients are also effective in treating dark spots on the face caused by the damaging rays of the sun. These products work by lightening the skin, replacing older skin with newer skin, and by slowing down the way the body removes skin cells that may have been harmed by the sun. Retinoid creams are one of the most effective delivery systems of tretinoin.

How can I prevent pigment problems?

The Skin Pigmentation Knowledge Center recommends these guidelines:

• The sun's ultraviolet rays are the main cause of sun spots or age spots. The best way to avoid getting them is to avoid the sun.

• Seek shade between 10am and 4pm, when the sun's rays are most intense. A good rule of thumb is to go indoors or cover up whenever your shadow is shorter than you are tall.

• Use sunscreens with a SPF (sun protection factor) of at least 15. (With an SPF 15 sunscreen applied properly, a fair-skinned person who sunburns in 20 minutes can tolerate 15 times 20 minutes -- 300 minutes -- without burning. Reapplication of SPF 15 or higher is necessary.)

• Wear light-colored, tightly woven, protective clothing and wide-brimmed (three-inch) hats.

• Sun protection should begin in childhood because it is estimated that 80 percent of lifetime sun exposure occurs before age 18.