Inflammation is a symptom of most auto-immune diseases. Usually the inflammation is caused by your own auto-immune system attacking your healthy cells.

Some examples Uveitis (eye inflammation), Crohn's (bowels), Reumatoid Artritis (Joints). Usually these diseases come in pairs, so some people are just more susceptible to whatever causes these diseases. Right now there is no cure but in the last decades huge progress has been made in suppressing these diseases using biologics, but they have the side effect of suppressing your immune system which may be dangerous.