Mansfield-born star Richard Bacon revealed he was 'quite close to death' for two days after suffering a mystery lung infection.
The 42-year-old former Blue Peter presenter - who was taken ill on a transatlantic flight earlier this month - said being told he needed to be put in a medical coma was 'the most shocking moment of my life'.
He told Radio 4's Broadcasting House a doctor later said: "There were a few points where I thought you were probably going to die."
Mr Bacon, a radio and television presenter who now lives and works in Los Angeles, said: "The first two nights went really badly - no one's fault - the infection was winning and my lungs were losing.
"My blood oxygen level went down to 70 per cent and when you go below 70 per cent basically you are looking at death or brain damage - but more likely death.
"I hit 70 per cent and for the first two nights, I have since found out, I came quite close to death."
Mr Bacon said that the illness had struck him when he was the fittest he had ever been 'by a country mile' because he had embraced a healthy 'LA lifestyle'.
But because he was in such good shape, he said, he put off going to Lewisham Hospital in south-east London until the day after the flight landed, despite having to be taken from the aircraft in a wheelchair.
Even after arriving in accident and emergency suffering from shortness of breath, he said he thought he would simply get drugs and perhaps be kept in overnight.
But he told how a senior doctor came in and dropped a bombshell, telling him: "It's much worse than that. I've looked at your x-ray and it's horrible."
"The doctor said 'I need to put you into an induced coma so that we can control your breathing and if I don't do that you are probably going to die'," Mr Bacon told Broadcasting House.
After spending more than a week in an unconscious state, he regained consciousness and was well enough to be discharged on Thursday.
On that day he tweeted: "Cleared for take off. Gone within the hour. I don't know whether I see this as the bed I nearly died in or the bed that saved my life. Either way. I won't miss it. But I will miss the 50 staff of Lewisham Hospital who definitely saved my life. Every. Single. One. Of. Them."