Joni Mitchell remains hospitalized several days after being rushed to the hospital after a collapse. Doctors say her condition is improving. Her medical scare has prompted people all over the world to wonder about the mysterious disease she claims to suffer from–Morgellons disease. What is it? More importantly–is it real?

The Mayo Clinic says Morgellons disease is both mysterious and controversial. It remains unexplained. People with the condition present with a skin disorder that is characterized by sores, crawling sensations on and under the skin, and fiber-like filaments emerging from the sores. It’s not certain what these strings are. Some say they are wisps of cotton thread, probably coming from clothing or bandages. Others say they result from an infectious process in the skin cells. Further study is needed.

Attitudes among medical professionals toward Morgellons disease tend to fall within three specific categories.

1. Some health professionals believe that Morgellons disease is a specific condition that needs to be confirmed by research.

2. Some health professionals believe that signs and symptoms of Morgellons disease are caused by another condition, often mental illness.

3. Other health professionals don’t acknowledge Morgellons disease or are reserving judgment until more is known about the condition.

In Joni Mitchell’s memoir, Joni Mitchell: In Her Own Words, the ‘Both Sides Now’ and ‘Big Yellow Taxi’ singer described how the disease affected her.

“I couldn’t wear clothing. I couldn’t leave my house for several years. Sometimes it got so I’d have to crawl across the floor. My legs would cramp up, just like a polio spasm. It hit all of the places where I had polio.”

Joni remains under observation in the hospital and is resting comfortably. Her progress is encouraging as she continues to improve each day.

— JoniMitchell.com (@JoniMitchellcom) April 4, 2015

Back in 2010, Joni Mitchell said she wanted out of the music business, so she could devote her time for raising awareness for and supporting those with Morgellons disease.

“Morgellons is a slow, unpredictable killer–a terrorist disease: it will blow up one of your organs, leaving you in bed for a year,” she said. “Morgellons is always diagnosed as ‘delusion of parasites,’ and they send you to a psychiatrist. I’m actually trying to get out of the music business to battle for Morgellons sufferers to receive the credibility that’s owed to them.”

CBS News reports that the U.S. Centers for Disease Control and Prevention has made efforts to respond to the Morgellons community by conducting investigations, and even at one point enlisting the U.S. Armed Forces Institute of Pathology and the American Academy of Dermatology to help with research. A handful of studies suggest Morgellons is simply an indication that a person may need to seek treatment for depression, skin-picking disorder, anxiety and even substance abuse.

Do you think Joni Mitchell is physically ill or has an illness that has caused delusions?

Either way, fans are no doubt happy to learn that the 72-year-old singer’s condition is improving, and that she will likely be released from the hospital before too long.