Published Friday, 16 October 2009
A statement on the band's website said "stress over a period of months has unfortunately taken its toll on Amelle and she is now suffering from a severe bout of nervous exhaustion."
Original member Keisha Buchanan left last month and was replace by Jade Ewen.
"Unfortunately, Amelle has been forced to take an unexpected short break away from the pressures of work, following some professional medical advice earlier this week."
For the next three weeks, Amelle will be staying at a private health clinic in Europe.
In a joint message her bandmate Heidi Range said: "Both Amelle and I have been through a very traumatic time together in recent months and particularly over the past few weeks."
"Having the opportunity to move forward with Jade was a major factor in us both deciding to carry on as Sugababes. And judging from the thousands of well wishes we have received from you, our fans, we are delighted that we made the right decision."