Britain's former prime minister Margaret Thatcher was admitted to hospital on Friday for "precautionary medical tests", the BBC reported.
Thatcher, 82, was taken to St Thomas' Hospital in south London, the broadcaster said. No other details about her condition were immediately available.
A spokeswoman for the Conservative Party, which Thatcher led for 15 years, said Thatcher had taken ill earlier on Friday
"We've been in touch with her office and sent her our best wishes," she said.
Thatcher has appeared only rarely in public in recent years after suffering a series of small strokes in 2002 which forced her to cancel her busy public speaking schedule.
As Britain's first and so far only female prime minister, Thatcher was dubbed the "Iron Lady", earning a reputation as one of the most formidable politicians of her era.
She came to power in 1979 and governed for more than 10 years before being ousted by members of her own party. She retired from the House of Commons in 1992.