'I was in agony' – Dermot Bannon reveals he suffered pulmonary ...

The RTÉ presenter (52) discovered he had a blood clot in both lungs while holidaying with his family for a week in Portugal.

The architect and Room to Improve star said it all started on the third day of the holiday when he took his two sons, Tom (12) and James (16), to a water park.

"We went away for a week's holidays, and now, thank God it was only a week's holidays," he told The Ray D'Arcy Show on RTÉ Radio 1.

"As the day went on in the water park, I was getting more and more tired. I was literally putting it down to old age.

"That evening, we got back to where we're staying, and I just said: 'I'm going to go for a quick sit down on the bed'. And I was in agony.

"Got into the bed and I couldn't lie on my side, couldn't lie my back, couldn't lie on my front. I was there just: 'I bet I broke a rib on one of the water slides'. So I googled that and, of course, as soon as you google it, 'Yes, I definitely did'.”

Bannon was the only one insured on the rental car so he drove himself to hospital in Lagos. The medical team did an X-ray and thought it was a lung infection.

The Malahide native said the symptoms subsided but a week after he returned to Ireland, they came back.

"The pains came back, but more severe. Lying in bed at four o'clock in the morning, really sharp pains down my side,” he said.

He decided to visit the clinic the next day to get it checked.

"I went up to there, and she said: 'Yeah, you have a bit of a lung infection. It hasn't cleared up, but there could be something a bit more sinister. I’d like you to get a blood test done'. And I said: 'Grant. Next week?' She says: 'No, maybe now',” he said.

They did a blood test and CT scan in the hospital.

"I had what was known as a pulmonary embolism, which was a blood clot that came from my leg, had worked its way up, and was in both my lungs,” he said.

"If you don't do something, the pressure in your heart can cause a cardiac arrest because this oxygen is restricted.

"I was getting the news bit by bit, how this could have turned out if I hadn't acted the way I did. You can die from it.

"It's a clot. Unless they dissolve, they're blocking oxygen from going everywhere, and the pressure can build up because your heart has to work so much to try and pump oxygen around your body.”

He added the biggest health issue he had had prior to this was a root canal.

He said it was a week after being in the hospital before the reality of the situation hit him and sank in. He's now on blood thinners now and has upcoming appointments to monitor his health.

Bannon said he was putting everything down to "just getting a bit older". His dad had a heart attack at the age of 50.

"Because of that, I watch my food, I'm always doing a bit of exercise. I'm generally really good," he said.

Super Spaces starts tonight on RTÉ One and RTÉ Player at 9:35pm.