Missy Elliott has Graves' disease, an autoimmune disorder that attacks the thyroid.
"You live with it for the rest of your life," she tells People.
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According to the Graves' Disease Foundation
, the illness affects 2 to 3 percent of the population. Elliott, 39, was diagnosed in 2008 after suffering such symptoms as dizzy spells, lumps in her throat, mood swings, hair loss, a fast heart rate and bulging eyes. Her motor skills were also affected.She had been undergoing radiation and taking medication for the past three years and now is feeling better. "I'm 30 pounds lighter because I've been exercising," the rapper says. "My thyroid is functioning, so I haven't had to take medication in about nine months."Elliott's focus now is music: She's working on a comeback album with Timbaland