Lady Gaga has cancelled the last 10 dates of the European leg of her world tour due to "severe pain".
In a statement posted on Twitter, the pop star apologised to fans and said she was "devastated", but needed to put "myself and my well-being" first.
The Grammy award-winning singer has fibromyalgia, a long-term condition which can cause pain all over the body.
Shows in London and Manchester are among those affected.
In the statement, it said the "tough decision" had been made on Friday night with "strong support from her medical team".
Ticket holders can apply for a refund from 6 February, the statement added.
"I'm so devastated I don't know how to describe it," Lady Gaga, 31, wrote. "All I know is that if I don't do this, I am not standing by the words or meaning of my music."
The announcement comes after she started the UK leg of her tour at Birmingham Arena.
The European leg of her Joanne World Tour had already been rescheduled due to her condition and followed a decision to pull out of a performance at Rock In Rio in Brazil in September, after she was hospitalised with "severe physical pain."
The Born This Way singer was due to perform in Zurich, Koln, Stockholm, Copenhagen, Paris and Berlin in the coming weeks.
At the end of last year, the star announced a two-year residency in Las Vegas, starting late in 2018.