What Causes Lupus?

11. Ultraviolet Radiation

There are three types of radiation from the sun: UVA, UVB, and UVC. UVA has the longest wavelengths; UVC is the shortest. UVA rays can penetrate through the top layer of your skin; UVB, because they are shorter, cannot. Some UVA rays, called UVA2, and UVB can exacerbate lupus symptoms, while UVA1 may have protective effects.

People with lupus also need to be careful with some indoor lighting; halogen lamps, incandescent bulbs, and fluorescent bulbs all emit varying levels of UV radiation. Even low-level exposure can cause skin damage over time.