Sjögren syndrome is an autoimmune disorder in which the body's white blood cells attack and destroy other cells. It can exist by itself (primary Sjögren syndrome) or develop in association with another disorder such as rheumatoid arthritis, systemic sclerosis, primary biliary cirrhosis, or Hashimoto thyroiditis (associated Sjögren syndrome). Hallmarks are the dry mouth and dry eyes known as the sicca syndrome. Sjögren syndrome affects 1 million to 4 million people in the United States. Most are over 40 years old at the time of diagnosis. Women are 9 times more likely to have Sjögren syndrome than men. The disease is named after Swedish ophthalmologist (eye physician) Henrik Sjögren (1899-1986), who first described it. The July 28, 2010, issue of JAMA includes an article about treatment of primary Sjögren syndrome.