David Cameron could require a painkilling injection after revealing he has been suffering from a "phenomenally bad back".
During a family holiday on the Scottish island of Jura, the Prime Minister said a scan showed he had a protruding disc.
Mr Cameron, who enjoys deer stalking, said his back pain meant he avoided the hunting activity, which requires crawling on the ground.
His comments came during a pre-recorded interview with the BBC.
Mr Cameron said about the whisky-producing island: "It's a great place to unwind. I like the great outdoors. I like an active holiday.
"The people are incredibly friendly. It's just a great way to recharge your batteries.
"And when you're up a hill on a stiff walk and the rain's coming down and then glorious sunshine with these fantastic views - there's nowhere better to be."
The island is home to thousands of red deer and according to the Prime Minister deer stalking is "probably one of the most defendable" field sports. He also denied giving up hunting because of opposition to the sport by some people.
"I find now I'd rather go for a walk and this year I've got a phenomenally bad back so I really don't think I'll be able to crawl," he said.
"It's a lot of crawling through the heather sometimes for a very, very long time."
The prime minister said he also liked fishing and would occasionally swim in the sea.
"It's not actually as cold as some people think," Mr Cameron said.
"There is, I think, a bit of Gulf stream that comes up the west coast of Scotland. But when you get out you need to get in a hot bath pretty quick."
Mr Cameron joked that he liked horse riding but "not bare-chested" like Russian premier Vladimir Putin.
The Cameron family have left the island to continue their holiday in Cornwall.
In a tweet Mr Cameron revealed that he had received treatment for his back pain earlier today. He said: "I've been treated for a bad back/protruding disc at Nuffield Orthopaedic Centre today. The staff say all will be back to normal very soon."