The TV star, 32, revealed the ordeal lasted for about six hours and he was informed by doctors that it had been a panic attack.
Speaking on ITV Hub's brand-new series The Full Treatment, Jamie also discussed his first heartbreak as a teen and how Ronan Keating helped him with his parents' divorce.
Terrifying: Jamie Laing has revealed he suffered a panic attack shortly after he joined the cast of Made In Chelsea and went to the hospital because he 'thought he was dying' (pictured in 2020)Insurance Loans Mortgage Attorney Credit Lawyer
On his panic attack, Jamie said: 'I was twenty-two years old and suddenly I was like, 'I feel a bit weird' and I had a panic attack. I'd never had one in my entire life.
'I'd just started filming Made In Chelsea. This panic attack lasted six hours, I thought I was dying for six hours. So, I went to hospital and said, "I'm dying", they said, "No you're having a panic attack".
'That was six months of hell where I didn't tell anyone, (I) didn't speak up, I just dealt with this panic within me.
He added: '(One day) I was in the shower and I went, "what is wrong with me?" I said it out loud to myself and I was crying and that was the first time I said it loud. I went and told my mum and she took me to the doctors.
Scary: The TV star, 32, revealed the ordeal lasted for about six hours and he was informed by doctors that it had been a panic attack (pictured on Made In Chelsea in 2012)
'Being open and honest. Speaking to your friends is key. It doesn't matter if it's a stranger, your next-door neighbor or your dog, speak out about it. Exercise for me is the winner.'
Jamie also revealed how Ronan Keating helped him through his parent's divorce.
He said: 'My parents got divorced when I was ten years old and I found it hard because I was always scared they were going to get divorced for some