Sunburns are caused by exposure to too much ultraviolet (UV) light. UV radiation is a wavelength of sunlight in a range too short for the human eye to see. UV light is divided into three wavelength bands — ultraviolet A (UVA), ultraviolet B (UVB) and ultraviolet C (UVC). Only UVA and UVB rays reach the earth. Commercial tanning lamps and tanning beds also produce UV light and can cause sunburn.



The phases of a sunburn are actually your body's way of blocking the UV rays to prevent sunburn and other skin damage. But the protection only goes so far. The amount of melanin a person produces is determined genetically, and many people simply can't produce enough melanin to protect the skin well. Eventually, UV light causes the skin to burn, bringing pain, redness and swelling. Sunburn on brown skin should be carefully monitored as it is not as easy to detect.

You can also get sunburn on hazy or cloudy days. As much as 90 percent of UV rays pass through clouds. UV rays can also reflect off snow, ice, sand, water and other reflective surfaces, burning your skin as severely as direct sunlight.

People with fair skin are more likely to sunburn than people with brown skin. That's because people with darker skin have more melanin, which offers some protection from sunburn but not from UV-induced skin damage.

Skin color is determined by the number, distribution and type of pigment-producing cells (melanocytes) in the skin. Dermatologists refer to the degrees of pigmentation in skin as "skin types." Skin types range from very little pigment (type 1) to very darkly pigmented (type 6). How easily you burn depends on your skin type and how light or dark your skin is.

In the phases of a sunburn and regardless of your skin type, the sun's energy penetrates deeply into the skin and damages DNA of skin cells. This damage may ultimately lead to skin cancer, including melanoma. Even people with type 5 or 6 skin can develop skin cancer, often on the palms, fingers or other more lightly pigmented areas of their bodies.

In addition to skin type, living in a sunny or high-altitude climate increases your risk of sunburn. People who live in sunny, warm climates are exposed to more sunlight than are people who live in colder climates. In addition, living at higher elevations, where the sunlight is strongest, exposes you to more radiation and increases your chances of sunburn and skin damage.

The progression of a sunburn is as follows:

- Blistering may cover a large portion of your body

- Accompanied by a high fever, extreme pain, confusion, vomiting or diarrhea

- Doesn't respond to at-home care within a few days

Seek medical care if you notice signs or symptoms of an infection. These include:

- Increasing pain and tenderness

- Increasing swelling

- Yellow drainage (pus) from an open blister

- Red streaks, leading away form the open blister, which may extend in a line upward along the arm or leg

In summary, sun exposure that results in sunburn increases your risk of certain complications and related skin diseases. The phases of a sunburn progress from burn to infection, to premature aging of your skin and, finally, skin cancer. While sunburn on brown skin is harder to identify, it can be serious nonetheless.