Pop star Ashlee Simpson has returned to the United States after collapsing from exhaustion in Japan at the end of last week.
Simpson was performing at MTV's Cool Christmas concert in Yokohama, Japan when she stopped in mid-song and told the audience she was not feeling well.
She cut her performance short and returned to her hotel, before being taken to a local hospital.
Simpson's rep said doctors diagnosed the singer with exhaustion and she flew home on Saturday to her family in Dallas.
