Shelley, 34, was shown the door last night (20 October) after finding herself in the bottom two alongside boy band Kingsland Road.
Although she admits she it wasn't a "massive shock" that she was sent home by the judges, Shelley did reveal that she had spent the week feeling poorly.
Speaking on ITV1's Lorraine today, Shelley said: "There's been a virus going around the house.
"I was really ill - the day before I passed out. We've all been passing out.
"I passed out but I got on that stage and I was just glad that I got round that routine and sung my little heart out!"
Earlier today, we revealed how fellow contestant Abi Alton was taken to hospital on a stretcher after falling down a flight of stairs backstage.
Abi missed an appearance on The Xtra Factor but, luckily, she was soon discharged and returned to the contestants' house hours later.
If this wasn't enough, pregnant Miss Dynamix star SeSe Foster was also rushed to hospital on Saturday, meaning the girl band could not perform.
She later confirmed that both she and her baby were fine, adding that she had suffered an anxiety attack. It's certainly been very dramatic behind the scenes this year!
Meanwhile, Shelley has also said that she wasn't surprised to have been booted off the ITV1 singing show.
Speaking on an earlier Daybreak appearance, she also said: "I think I was ready for it - I thought it was going to happen so it wasn't a massive shock.
"I think because I was the bottom of the vote the first week I thought probably…I kinda expected it. I was hoping not to be but it doesn't matter - I'm fine."
Watch Shelley's 'Single Ladies' performance below: