Glenn Beck Glenn Beck

Glenn Beck revealed he's been battling a rare neurological illness and that's the reason he came off so "crazy" while at Fox News.

In a video posted on The Blaze, Beck said that he's been battling the disease for five years, which resulted in pain so bad that "my hands or feet or arms and legs would feel like someone had crushed them or set them on fire or pushed broken glass into my feet."

Beck, who left Fox in 2011, revealed that the symptoms of his health issues — including vocal cord paralysis and "strange" eyesight problems — "quite honestly has made me look crazy. And quite honestly, I have felt crazy because of them."

Glenn Beck mocks himself on final Fox News show

"We went to doctor after doctor. We even looked into someone poisoning me," Beck said. "Each doctor had a new finding and they left me with more questions and no answers... It has baffled some of the best doctors in the world it has frightened me and my family."

Eighteen months ago, Beck took a traumatic brain injury test, in which he tested in the bottom 10 percent. Doctors then informed him that he would have five to 10 years before he would lose all ability to function. Refusing to lose hope, Beck began pursuing treatments for his ailments — which include an autoimmune disorder and an adrenal shutdown —  with "electric stimulation," through which he's been able to help reverse the adrenal shutdown. He revealed that on his most recent traumatic brain injury test, he tested at 90 percent capacity.

"My brain is back online in a big way," Beck said.

Watch Beck's reveal below.