Demi Lovato was rushed to hospital on Tuesday after experiencing significant breathing difficulties.
A friend of the singer took her to the emergency room at Providence Tarzana Medical Center in California, according to TMZ.
Doctors performed a number of tests and decided the problem was flu-related and prescribed a variety of different medications.
Demi is understood to have remained in hospital on Tuesday and has been quiet on social media since.
The star has been inundated with well wishes from fans after they heard the news.
One person tweeted: “Literally all I read was ‘Demi Lovato rushed to ER’ and my heart stopped….my baby girl is sick. Get well soon muffin head.”
Another person wrote: “I hope everything is okay. Get well soon, beautiful. Make sure to get lots of rest and I’ll definitely pray for you. I love you.”
Get well soon, Demi!
GALLERY: Demi Lovato's puppy buddy
Demi Lovato's puppy Buddy
1 of 18Ermahgerd!
2 of 18Too much!
3 of 18Jeez...
4 of 18Can't. Stop. Looking.
5 of 18So much Buddy love!
6 of 18He woke up like this
7 of 18DEMI IS SO LUCKY!
8 of 18He's smiling! He's actually smiling!
9 of 18Enjoying a grande, quad, non-fat, one-pump, no-whip, mocha, eh?
10 of 18Nice sweater...
11 of 18Incredible
12 of 18So, so soft
13 of 18Buddy's first dressing room!
14 of 18Is there anything cuter than a dog in a bag?
15 of 18Catching up on some Zzzzzzzz
16 of 18The paws! The tiny paws!
17 of 18Buddy's first Christmas!
18 of 18