Cher’s ordeal at the hands of the has been well-documented over the years, and the pop diva has never kept her condition a secret.

In 1992, Cher took some time off from her career and it was widely reported that the virus was responsible. “My experience was it was really a physical illness but it does make you depressed as well,” she told the . “It’s a virus you have it’s called Epstein Barr virus and the disease it gives you is chronic fatigue.”

“Boy, it was devastating for me…I wasn’t able to work for almost three years,” the singer added.

Chronic Fatigue Syndrome (CFS) is also known as post-viral fatigue syndrome and occurs after the sufferer has been infected. The Epstein-Barr virus itself is a relatively common condition found in adults. It can lie dormant, but in 50% of cases progresses to infectious mononucleosis, causing symptoms such as fever and swollen lymph glands, according to the .

The virus remains in the body even after symptoms have passed and can reactivate at any point. The effects of CFS are similar and, like with Epstein-Barr virus, treatment is only available for the relief of symptoms and not the cause.

In Cher’s case, the symptoms were so severe, she feared for her life. “I was sick a long time,” she told . “I went to Germany for some medicine and treatment. They have things overseas we never dreamed existed. When I was first diagnosed in the late ’80s, I had doctors telling me I was crazy. I was sick constantly and almost died from pneumonia. You never lose it, and it really takes the life out of you.”

The star reportedly suffered another bout of illness in 2008 and had to delay several shows as a result, although her publicist claimed at the time that Cher contracted “Vegas throat – a condition caused by the dry desert air in the region, the reported.

Images: PR photos