Listen to Miley Cyrus on iHeartRadio

(TMZ) - Miley Cyrus' hospitalization was triggered by a sinus infection gone horribly wrong, TMZ has learned.

Reps for Miley tell TMZ, the singer got an Rx for an antibiotic called cephalexin (brand name Keflex) to treat a sinus infection after getting diagnosed last week in North Carolina.

According to TMZ, within days Miley's throat swelled to the point she could barely talk. She was rushed to the hospital Tuesday night and, according to her rep, doctors determined she had an extreme allergic reaction to the drug.

TMZ reports Miley never got a cephalexin script before so she had no idea she was allergic.

She'll remain hospitalized until her condition improves. Her doctor says an allergic reaction of this kind can last 27 days.

Get well soon Miley! 

Photo Credit Getty Images