Christina Applegate , Reveals Multiple Sclerosis, Diagnosis.<br />Applegate, 49, took to Twitter in the early hours of Aug. 10 to share the news.<br />Multiple sclerosis, often called MS, is an autoimmune disease that affects the central nervous system.<br />MS causes a person's immune system to attack its own healthy cells, which can be disabling.<br />There is no cure for MS, <br />but symptoms can be managed.<br />According to the National Multiple Sclerosis Society, over 2.3 million people have been diagnosed with MS globally.<br />According to the National Multiple Sclerosis Society, over 2.3 million people have been diagnosed with MS globally.<br />and nearly 1 million people over the age of 18 have been diagnosed with the autoimmune disease in the U.S.<br />The exact cause of MS is unknown, but researchers believe it is the result of genetic and environmental factors.<br />Other celebrities who've been diagnosed with MS <br />include Selma Blair, Jack Osbourne, Art Alexakis, <br />Jamie-Lynn Sigler, Montel Williams and more.<br />Other celebrities who've been diagnosed with MS <br />include Selma Blair, Jack Osbourne, Art Alexakis, <br />Jamie-Lynn Sigler, Montel Williams and more.<br />Other celebrities who've been diagnosed with MS <br />include Selma Blair, Jack Osbourne, Art Alexakis, <br />Jamie-Lynn Sigler, Montel Williams and more.<br />Other celebrities who've been diagnosed with MS <br />include Selma Blair, Jack Osbourne, Art Alexakis, <br />Jamie-Lynn Sigler, Montel Williams and more.<br />Other celebrities who've been diagnosed with MS <br />include Selma Blair, Jack Osbourne, Art Alexakis, <br />Jamie-Lynn Sigler, Montel Williams and more.<br />Other celebrities who've been diagnosed with MS <br />include Selma Blair, Jack Osbourne, Art Alexakis, <br />Jamie-Lynn Sigler, Montel Williams and more
