Birthmarks: The dark marks come in various shapes and sizes, appearing at birth or soon after in shades of red and brown. Some are related to blood vessel deformities occurring as early as the embryo’s first month.

Treatment: Some types disappear during childhood — for other, lasers can often reduce or obliterate the lesions.

Age Spots: These spots, which often appear on the face, chest and hands as we age, are technically known as solar lentigo. Don’t mistake them for freckles — age spots tend to be larger and more irregular in shape. Age spots appear when sun damage throws off the patterns of pigment-producing melanocytes.

Treatment: Chemical peels and laser procedures can help make age spots disappear.

Melasma: These brown stains on the face or chest are more common in women, often after pregnancy, after menopause, and can sometimes also be related to birth control. Hormones from pregnancy or the oral contraceptive pills can increase the body’s production of melanin, which can land unevenly in different areas. Exposure to the sun keeps the melanocytes (cells which produce melanin) stimulated and keeps the makes the stains persist. Avoiding the sun and using sunscreen on a regular basis can help reduce the marks and prevent additional areas from forming.

Treatment: Options range from topical creams, to light glycolic acid peels, to fractional laser resurfacing for resistant remnants.

Vitiligo: This total loss of skin pigment and affects 1 percent of the population. The condition is autoimmune in nature, meaning the bodies own immune cells attack pigment cells which ultimately leads to bleaching of the skin.

Treatment: Many topical creams are available to help combat the condition.