Stevens shared the news with his fans in a post on his website on Wednesday morning.

“Last month I woke up one morning and couldn’t walk. My hands, arms and legs were numb and tingling and I had no strength, no feeling, no mobility,” he wrote. “My brother drove me to the ER and after a series of tests — MRIs, EMGs, cat scans, X-rays, spinal taps (!), echo-cardiograms, etc. — the neurologists diagnosed me with an auto immune disorder called Guillian-Barré Syndrome.”

According to the World Health Organization, in Guillain-Barré syndrome, the body’s immune system attacks the peripheral nervous system, which can affect nerves that control muscle movement and can result in muscle weakness, loss of sensation in the limbs and problems swallowing or breathing.

The Grammy-nominated artist added that he had been “stuck in bed” in the hospital for weeks while a medical staff worked on stabilizing his condition. He called the experience “very scary.”

For the past few weeks, Stevens has been undergoing “intensive physical therapy/occupational therapy, strength building etc. to get [his] body back in shape and to learn to walk again.”

The “Mystery of Love” singer has kept an optimistic mindset throughout the process.

“Most people who have GBS learn to walk again on their own within a year, so I am hopeful,” he wrote. “I’m only in my second week of rehab but it is going really well and I am working really hard to get back on my feet. I’m committed to getting better, I’m in good spirits, and I’m surrounded by a really great team. I want to be well!”

Stevens also noted that his medical setbacks have prevented him from promoting the release of his highly anticipated 10th album, “Javelin,” which is scheduled for an Oct. 6 drop.