Lupus is a disease that occurs when your body's immune system attacks your own tissues and organs (autoimmune disease). Inflammation caused by lupus can affect many different body systems — including your joints, skin, kidneys, blood cells, brain, heart, and lungs. 

Lupus can be difficult to diagnose because its signs and symptoms often mimic those of other ailments. The most distinctive sign of lupus — a facial rash that resembles the wings of a butterfly unfolding across both cheeks — occurs in many but not all cases of lupus.

Some people are born with a tendency toward developing lupus, which may be triggered by infections, certain drugs or even sunlight. While there's no cure for lupus, treatments can help control symptoms.

No two cases of lupus are exactly alike. Signs and symptoms may come on suddenly or develop slowly, may be mild or severe, and may be temporary or permanent. Most people with lupus have mild disease characterized by episodes — called flares — when signs and symptoms get worse for a while, then improve or even disappear completely for a time.

If you have lupus, sun exposure can trigger symptoms such as skin rashes, itching, burning, joint pain, weakness, and fatigue. In some cases, it can even cause organ damage 

People with lupus are particularly susceptible because they experience greater sensitivity to sunlight. If you have lupus, protecting yourself from sun exposure is an essential part of managing your condition.

Ultraviolet (UV) light is a type of invisible radiation that’s present in sunlight. Exposure to it can damage and even destroy your skin cells.

In healthy people, the body efficiently removes these damaged cells and heals any resulting sunburn or irritation. But if you have lupus, this process doesn’t work as well. For this reason, UV light can trigger lupus flare ups.

According to the Lupus Foundation of America, 40-70% of people living with lupus will experience flare ups from exposure to UV rays from either sunlight or artificial light. 

There are three types of UV light: UVA, UVB, and UVC. Research shows UVB rays can cause problems in people with lupus, triggering symptoms such as:

• lupus rash or lesions

• fatigue or weakness

• joint pain

• tingling or numbness

This means that exposure to sunlight can not only trigger skin symptoms, but also systemic symptoms, affecting the entire body.