Missy ElliottIt’s been quite a few years since Missy Elliott has been front and center on the scene, making an impact. But apparently, one of the reasons for her absence is a disease she was diagnosed with nearly four years ago.

The 39-year-old announced this week that she is suffering from Graves’ disease, an autoimmune disorder that leads to over-activity of the thyroid gland.

Elliott revealed to People that she was diagnosed with the disease in 2008, when she first began showing signs of the disease.

“I was [driving and] trying to put my foot on the brake, but my leg was jumping. I couldn’t keep the brake down and almost crashed,” Elliott told the mag. “I couldn’t write because my nervous system was so bad — I couldn’t even use a pen.”

Since Elliott found out, she’s been receiving radiation treatment to help alleviate symptoms — including dizzy spells, lumps in her throat, mood swings, hair loss, and bulging eyes.

According to Missy, the radiation helped, but other medication made her pack on the pounds, which she’s tried to counter via exercise.

The disease isn’t fatal, but after treatment, Missy says things are much better.

“My thyroid is functioning, so I haven’t had to take medication in about nine months,” she said.

The rapper will talk about her condition more, and even open up about childhood sexual abuse in an upcoming VH1 “Behind The Music” special, set to air on June 29.

“Missy was great and very candid. She talked for the first time about her [near fatal bout with] Graves disease, which she’s been battling for the last few years, and spoke in detail about the sexual abuse she experienced as a child,” executive producer Brad Abramson told Vibe.com.