The 26-year-old singer gave an update on Hemsworth's health in an Instagram post Monday after attending the Los Angeles premiere of the actor's movie Isn't It Romantic in his stead.
Cyrus shared a photo of herself on the red carpet at the event. She wore a red Valentino gown with ruffle detail and a train.
"So proud of my hunky hubby @liamhemsworth & his newest movie #IsntItRomantic," the star captioned the post. "He unfortunately wasn't able to attend due to health reasons... but he is recovering and taking this time to rest/heal."
"It's hard for entertainers to put themselves before the project but this time it was crucial .... I am proud to represent him and his incredible work," she said. "So happy to see him shining in this comedy! He is the funniest person I know, and the world now gets to see the Liam I wake up to every day.... luckiest."
The "Nothing Breaks Like a Heart" singer also spoke to reporters at the premiere.
"I was all dressed up. My man's not well. I'm representing for him," she said, according to USA Today.
Isn't It Romantic star Rebel Wilson had told Extra during a press day Sunday that Hemsworth was absent due to illness.
"He texted us this morning. He was in hospital overnight, so hopefully he will be fine," the actress said.
Hemsworth failed to join Cyrus at the Grammys ceremony Sunday evening. Cyrus instead brought her parents, Billy Ray Cyrus at the Tish Cyrus, to the awards show, where she performed with her godmother, country star Dolly Parton.
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Rebel Wilson, Miley Cyrus attend 'Isn't It Romantic' premiere