A spokesman for Amy Winehouse says the 24-year-old soul diva is having more hospital tests after fainting earlier this week.
Spokesman Chris Goodman says Winehouse had more scans and tests Thursday.
Winehouse collapsed Monday at her north London home after signing autographs for a group of fans. An assistant caught her before she hit the ground.
She is scheduled to sing at a June 27th concert to celebrate Nelson Mandela's 90th birthday, and is due to take part in the Glastonbury music festival the next day.
Her spokesman says that although Winehouse still plans to perform at both concerts, the decision "will be made entirely on the advice of her doctors and in her best interests."