The 24-time international suffered a mini-stroke in 2014, the morning of Ireland's test match against South Africa.

"It was one of the biggest life-events, shocks to me in my life," said the Six Nations champion.

"The morning of the match, I woke up, feeling really good and ready to play and get stuck into a big, big test match in Dublin.

"I went into the bathroom and put water on my face and my left-hand side of my arm just fell into the sink.

I looked up and the side of my face dropped. I lost all my speech.

"Because of my father having a stroke before he passed on, I kind of knew the symptoms but I just turned 30 years of age so I was going, 'how on earth can this be happening?'"

Henry said he managed to mumble to his room-mate, Rhys Ruddock, who saw something serious was happening and he rushed to get the doctor.

"Within four or five minutes, thankfully all my strength came back. My speech came back, my strength in my arm came back.

"Terrifying, I guess, is the only way to put it. At that stage, rugby definitely went in the back burner.

"It wasn't about 'oh am I ever going to play rugby again?' It was 'is this going to happen again? Am I going to be driving home or doing something in daily life and this happens again or far worse?'

Henry was in hospital for about four days getting tests and doctors got to the bottom of the issue quickly.

"They realised I had a hole in my heart. Because of that, a clot went into my heart and instead of getting cleaned out through the lungs it went up into the brain.

"A terrifying time. I had a procedure to close the hole in the heart, so thankfully that's closed."

The 33-year-old says he was thrown back into playing quickly and while he was scared, the feeling of getting back and the support he received was something he cherishes.

For me, I just feel very lucky that I can still do what I love. I can still play and have no lasting side-effects from it.

Henry also talked about the loss of Nevin Spence which he says was difficult to take.

"Losing Nevin, a teammate and a good friend like that...it's still hard to comprehend I guess, and get your head around. It's something that just shouldn't have happened.

"He was a fantastic young man. In a selfish way, I guess it helped me get to terms I guess with my own father. It's something I'll never be able to understand.

"What Ulster have done with the museum and the wee bits and pieces that we have of Nevin around the stadium - it's wonderful.

"It's a way of us really remembering what a proper, true person he was and what we all try to aspire too and stand for. It's incredible to think what he could have gone on to achieve.

Watch the full interview here: