Miley Cyrus is suffering from "the worst stomach flu of all time".

The 21-year-old pop star recently came down with the illness and took to Twitter on Sunday to share how bad she felt with fans.

Referencing a lyric in Daft Punk's hit track Get Lucky, she tweeted she was "up all night to get pukey", before confessing she was dealing with "the worst stomach flu of all time".

The pop star's messages came just hours after she became tangled in a lawsuit filed by the promoters of the Miami South Beach Outdoor Festival.

TMZ reports the plaintiffs claim a woman claming to be the star's booking agent took a $125,000 deposit to secure Miley for the New Year's Day event but she never showed.

The star's people reportedly denied any involvement in the deal.

A spokesperson for the singer has not yet issued a public comment.

Miley is in the midst of getting ready for her Bangerz World Tour, scheduled to kick off February 14 in Vancouver. The trek will then move to the US and other parts of Canada before heading to Europe.

She admitted back in November she was having "meltdowns" about how the shows will be received.

"I'm ready to be on tour already. I wish I could skip past all the tours and all the rehearsals and all that and how many meltdowns 'cause I get very anxious," she told MTV News.

"It keeps getting better and obviously I'm excited about my tour. I get nervous that I'm gonna get there and no one's going to show up, but hopefully some people show up."