Sjogren's is a chronic autoimmune disorder that is often - but not always - marked by dry eyes or mouth. But Sjogren's is "a hard diagnosis to make because there is no single sign, symptom, or complaint" that defines it, says Dr. Robert F. Spiera, director of vasculitis and scleroderma programs at New York City's Hospital for Special Surgery. And it doesn't help things that Sjogren's sufferers often complain not of dryness but of less specific symptoms, such as fatigue or aches. If you're tired and suffer from dry eyes or mouth along with joint pains, alert your doctor to all those symptoms. Blood tests can help confirm the diagnosis.