The Big Difference Between Fibromyalgia And Lupus

Lupus and fibromyalgia are two diseases that few understand. They're relatively uncommon, with lupus affecting about 1.5 million Americans according to the Lupus Foundation of America and fibromyalgia affecting roughly 4 million Americans according to the Centers for Disease Control and Prevention (CDC). It's actually possible for one person to have both diseases, says the Hospital for Special Surgery, though official diagnosis is difficult because the conditions have almost identical symptoms. These include fatigue, numbness, headaches, stiffness, and muscle or joint pain.

Despite the similar symptoms, the diseases require very different treatments. Thankfully there are ways that doctors can tell the conditions apart, but they require a keen eye and more in-depth diagnostic practices than looking at symptoms alone.

The Hospital for Special Surgery explains that the biggest difference between lupus and fibromyalgia is the way the conditions affect muscles and joints. People with either condition will often experience whole-body pain and stiffness. In the case of lupus, these sensations are accompanied by swelling around the joints and inflammation in the muscles. If someone has fibromyalgia, however, the joints and muscles will appear normal. But why is this?

As the Hospital for Special Surgery explains, lupus is an autoimmune disorder. Lupus causes the body's immune system to go into overdrive. The National Center for Biotechnology Information states that when our bodies send immune response cells to an area, these cells release chemicals that dilate the blood vessels where there is a perceived irritant like a virus, bacteria, or foreign object. In the case of lupus, the body is overreacting and actually harming itself.

Fibromyalgia, on the other hand, is not an autoimmune disorder (via Healthline). It doesn't cause inflammation and, as explained by the Arthritis Foundation, bloodwork on fibromyalgia patients normally comes back normal while the blood of lupus patients will contain high levels of antinuclear antibodies. These are proteins produced by the immune system and are often overproduced in people with autoimmune disorders like lupus (via MedlinePlus). 

So while the two conditions overlap in many ways, there are distinct differences in how the conditions affect the body. And the root of those differences lies in the fact that lupus is an autoimmune condition while fibromyalgia is not.