Zara Larsson has pneumonia.

The 19-year-old singer has taken to social media to announce she has contracted the inflammatory condition - which is the swelling of the tissue in the lungs caused by a bacterial infection - just days before her 20th birthday on Saturday (16.12.17).

The 'Never Forget You' hitmaker posted on Twitter: ''I have pneumonia uugghh (sic)''

And the pop star has revealed she is currently taking a variety of medication, has even been prescribed an inhaler and has been advised by medical experts to rest for ''10 days'' to help her recover.

She posted: ''Antibiotics, cortisone and inhaler and rest for 10 days ... and it's my birthday on Saturday (sic).''

Since sharing the news, Zara has been swamped with sweet get well soon messages from her fans.

One follower replied: ''Awh my dad has it too ): I hope you get better soon (sic).''

While another fan wrote: ''Oh no, that's terrible!!! get well soon and please try not to go outside until you get better, take your medicines, grab a blanket and stay warm and cozy, I love you!!! (sic).''

This news comes shortly after Zara wrapped up her final gig of the year just two days ago.

Alongside a string of images of her backstage with her band, which was posted on her Instagram account, she wrote: ''Last gig of the year. (sic).''

Zara's illness has no doubt impacted on her plans as she was desperate to get ''back in the studio'' to work on new music as soon as she performed her last concert.

The post continued: ''Now, let's get back in the studio. (sic)''