Sir Elton John suffered a "potentially deadly" bacterial infection during a tour, forcing him to spend two nights in intensive care and cancel concerts in the US, his management says.
The singer became violently ill at the end of a tour of South America last week, requiring him to return to the UK for urgent treatment.
Nine concerts that were due to be staged in Las Vegas and California over the next two weeks have been cancelled.
Sir Elton is now resting at home.
A statement by his management said infections of the kind suffered by the star were "rare and potentially deadly". It gave no other details.
"Thankfully, Elton's medical team identified this quickly and treated it successfully. He is expected to make a full and complete recovery," it added.
Sir Elton is due to resume his schedule of live performances in the UK on 3 June.
"I am so fortunate to have the most incredible and loyal fans and apologise for disappointing them. I am extremely grateful to the medical team for their excellence in looking after me so well," the star said.
His Million Dollar Piano tour is due to end its run in May 2018.
It is not the first time Sir Elton has battled a serious bout of ill-health.
While performing his show The Million Dollar Piano at Caesar's Palace in Las Vegas, Nevada in May 2012, Sir Elton became ill with a serious respiratory infection. Following his doctor's recommendation, he cancelled the show's last four concerts.
In July 2013, he had to cancel a concert in London's Hyde Park when he was diagnosed with appendicitis, which required urgent surgery.
"I knew I was sick but I didn't know I had such a dangerous thing inside of me until I had a scan, which was after nine shows, 24 flights and a summer ball. I could have easily died," he later said in an interview with The Telegraph.
The career of Sir Elton spans five decades and has been littered with accolades, hit singles and world records.
The 70-year-old singer has sold more than 200 million records, making him one of the most successful artists of all time.