WATCH: Dad sleeps for up to 22 hours a day due to rare disease

Jonathan Sheldon, 39, had been an active man before being diagnosed with Addison's secondary disease and M.E., chronic fatigue, after having chicken pox in 2013.

This initially left him sleeping for up to 22 hours most days. Eventually this time reduced and after 18 months he went back to work - but due to recurring ailments he had to leave.

His conditions have massively restricted his life and are life threatening if not managed correctly.

This means he could slip into a coma at any time if not properly medicated and even die if he is not treated. His wife Nicola, 41, has said they live "with the fear he will go to sleep and not wake up".

Opening up on his condition, former hedge-fund manager Jonathan, of Billericay, Essex, said: "It's the last thing I ever expected to happen to me. It's been a downward spiral from the fatigue.

"It had been about 20 years since I'd seen a doctor - even though I'd always been into outdoor stuff. If I ever got injuries I'd just fix it myself. "