Brandon Block left the Celebrity Big Brother house and was "rushed to hospital" in the week.
The incident is said to have happened in the house on Thursday but has only come to light today.
Reports have claimed that Brandon complained of chest pains and was first seen by an on-site medic.
However he was then taken to hospital over fears his condition could worsen.
“Brandon wasn’t well at all. It was pretty serious," a source told the Daily Star on Sunday newspaper. “He immediately saw the medics that were on standby at the house.
“But there were concerns his condition could worsen and could even become critical so it was decided he needed to go to hospital.”
Fortunately, Brandon was eventually given the all clear and returned to the house with no mention of his hospital dash was made on the show.
CBB sources say he is now being monitored around the clock by producers.
The insider explained: “They don’t want to risk the health of any housemate and if he has chest pains again, they will be ready to get him to hospital.
“They will also make a decision when it comes to each task on whether or not he should take part.”
Brandon is the second housemate to head to hospital this year after one half of Jedward lasted just 12 minutes in the house.
Edward was forced to take a trip to A&E after falling off stage during his entrance into the show on Friday night.
Celebrity Big Brother 2017 continues nightly on Channel 5.