The TOWIE star, 23, posted the worrying picture from her sick bed, where she can be seen with an IV tube injected into her arm.
On her wrist, Sam is wearing a hospital name tag.
Alongside the hospital selfie, Sam wrote: "Just woke up."
She also posted a 'sad face' beside the comment.
Many of her 16,000 Twitter fans responded to wish her well, including one celebrity tweeter...
The Saturdays' star Una Foden wrote: "@SamanthaFaiers hope you ok? You came across so lovely in that house, fair play to you for being such a lady and an example to women x."
Although Sam returned to social media to thank Una personally, she did not say how she was feeling.
Sam was the eighth contestant to leave the Celebrity Big Brother house during the final last week.
After leaving, she admitted she'd been ill during her time in the house and had to be admitted to the hospital for tests twice during her stay.
Sam told ITV's This Morning on Friday (31 January): "My experience compared to everybody else was so different and I'm absolutely gutted.
"For two weeks I couldn't hold food down whatsoever, and I still haven't had my results back from the hospital and I was in and out of hospital while I was in there as well. I went in there twice for blood tests and scans and it was really serious."
We wish Sam a speedy recovery.
What do you think of this story? Tell us below!