X Factor contestant Lucy Spraggan said she was "gutted" after being forced to leave the ITV show because she is not well enough to perform.
The singer pulled out of last weekend's shows and received a free pass to this week.
But since she is not well enough to perform this weekend, Spraggan said she felt it would be unfair to accept another free pass.
"I am gutted not to be able to continue on this journey but I'm not well enough to perform. To accept another free pass having missed last weekend would not be fair on the others in the competition," said Spraggan.
"There is no way that this setback will prevent me from fulfilling my ambition. You'll be hearing from me again very soon."
Spraggan will not be replaced in the competition and one act will leave the show this weekend, organisers said.
An X Factor statement read: "Lucy isn't well enough to perform this weekend so she has decided to withdraw from the competition.
"We are all sorry to see her go and wish her all the best for the future. She has been a fantastic contestant."
The singer's mentor, Tulisa Contostavlos, said:
I'm so sorry to lose Lucy from the competition, I have had a brilliant time working with her and I hope I can continue to mentor her in the future. I now count her as a friend as she is an amazing girl