Wasps captain James Haskell has revealed how doctors feared he had contracted meningitis after he was rushed to hospital with a virus last week.
Haskell missed Wasps' recent European Rugby Champions Cup clash at Leinster with an illness he thought was only flu until the club doctor visited him at his home and suspected something more serious.
He was sent to hospital in an ambulance where, after several tests, Haskell said he was left at "rock bottom", fearing he would miss England's opener for the autumn international series against New Zealand on November 8.
"I've never been that ill in my life," Haskell told the Times. "The Wasps doctor came and visited me at home and said 'there's something wrong with you'. They put me into hospital.
"They thought that I had meningitis and that was the big concern. That's why they put me in an ambulance. They were saying 'you can't mess around with that'.
"They knew it wasn't bacterial meningitis, but they thought it might be the viral version because I had a bad migraine and all the symptoms of it. They [the doctors] got me straight on to the antivirals and antibiotics.
"I got better a little bit, so they stopped some of the stuff and the next day I hit rock bottom again. They weren't sure what was going on, so they did a lumbar puncture and took fluid out of my spine, and numerous blood tests.
"They couldn't work it out. I couldn't open my eyes because they were too sensitive to light. My lower back and my neck were very stiff, so I couldn't really move out of bed at all. I spent hours lying in bed with a cold flannel on my head, in a dark room, on a drip, not eating or drinking.
"I'm not one of these people who looks symptoms up online because it's more dangerous than it's worth. A lot of people around were making a fuss but I actually stayed quite calm.
"I knew this [the autumn series] was coming up, I knew I was in a good place, I had been playing well and I just wanted to keep that momentum going. I did everything the doctors told me to do, I didn't overly panic and I tried to rest."
Haskell was released last Friday before he returned to training on Tuesday, some 11lbs lighter than he had been before suffering the illness.