Sjogren's syndrome is an autoimmune disease. This means that your immune system attacks parts of your own body by mistake. In Sjogren's syndrome, it attacks the glands that make tears and saliva. This causes a dry mouth and dry eyes. You may have dryness in other places that need moisture, such as your nose, throat, and skin. Sjogren's can also affect other parts of the body, including your joints, lungs, kidneys, blood vessels, digestive organs, and nerves.