Barnes posted the health update on his Instagram account on Saturday.
The 68-year-old rock icon posted a photo of himself smiling in a hospital bed with his wife Jane Barnes.
"I had a twinge in my hip when I was leaving Dunedin on Thursday morning and by late last night the pain was unbearable so I went off to hospital," the singer said.
"The doctors have recommended a remedial medical procedure ASAP followed by some physio to address the issue.
"These doctors don’t muck around! Providing all goes to plan, I’m expected to make a full recovery in six weeks."
It's unclear if the tour dates will be cancelled or postponed, with Barnes saying the "August and September solo shows will all be impacted".
"Ticket holders will be contacted with further info in the coming days once we have new plans in place," he said.
"I apologise for the inconvenience this will cause everyone – I HATE moving shows! — but thank you for understanding."
Barnes is currently on his Hell of a Time solo tour, which had seven more shows booked in Queensland and NSW.
He has also committed to a national tour with Cold Chisel to celebrate the 50th anniversary of the band.
The Big Five-0 Tour is due to kick off in October.
The first show will be held in the NSW city of Armidale, where the band was based back in 1974, and has already sold out.
In Saturday's social media post, Barnes didn't say whether the Cold Chisel tour would be impacted, but made a point of saying his solo shows were affected.
It's not the first time we've seen happy snaps of Barnes in a hospital bed.
In November, he cancelled a festival appearance after being put on bed rest to recover from a bacterial pneumonia in November.
But two weeks later the bacterial infection spread to his heart and he had to have open-heart surgery.
The infection had spread to a valve in his heart, which had been replaced years prior because of a congenital defect.
He said surgeons needed to "clear out [the] infection and put in a clean valve".
We acknowledge Aboriginal and Torres Strait Islander s as the First Australians and Traditional Custodians of the lands where we live, learn, and work.
This service may include material from Agence France-Presse (AFP), APTN, , AAP, CNN and the BBC World Service which is copyright and cannot be reproduced.
