Lupus and RA are both autoimmune diseases that often get mistaken for one another because they share many symptoms. A few of these common symptoms include joint pain, joint swelling, hot and tender joints, fatigue or weakness, or unexplained fever.
However, lupus is an autoimmune disease where your immune system attacks your body’s cells, which triggers inflammation and can lead to damage to healthy tissue. Thus, unlike people with RA, people with lupus also experience more issues involving their internal organs and skin. Lupus can also result in life-threatening complications such as kidney failure, blood clotting issues, or seizures.
Meanwhile, RA mainly affects the joints such as your fingers, wrists, knees, and ankles. RA can also lead to deformation and stiffness of joints (which usually does not occur in lupus). RA pain also tends to be worse in the morning, and it gets better as the day progresses. With lupus, joint pain may be constant throughout the day, and it can migrate. RA may also affect internal organs by causing inflammation to the ear and lungs, but it does not usually affect the kidneys (while lupus does).