Former Prime Minister Baroness Thatcher has left hospital after being given a "clean bill of health" by doctors.
Baroness Thatcher was described as a 'model patient' by staff
She walked out of London's Chelsea and Westminster Hospital telling reporters: "I'm fine, I'm fine. I feel fine."
Lady Thatcher, 80, who has suffered a series of strokes, spent the night in the hospital after complaining of "feeling faint".
She underwent a series of tests at the hospital, where she was treated as an NHS patient in its coronary care unit.
Her private secretary Mark Worthington said she had been seen by doctors and been given a "clean bill of health".
Lady Thatcher felt ill while visiting her hairdresser but Mr Worthington said her hair cut had been finished in hospital, adding that staff had described her as a "model patient".
The BBC's political correspondent Sean Curran said the former prime minister had praised the "wonderful" staff at the hospital.
Lady Thatcher was treated in a separate room for "security reasons", but was treated as an NHS patient, he added.
Earlier Mark Purcell, spokesman for the Chelsea and Westminster Hospital, said the former prime minister had had a comfortable night.
Former Thatcher adviser Lord Bell said Lady Thatcher had been keen to go home and had begun to be "difficult".
He told the ITV News Channel: "I do not think anyone overreacted, but they were very cautious. She was looked at last night. They did a few tests and everybody was very happy.
"I was told this morning that she was beginning to be difficult, which is usually a very good sign that she is feeling fine."
Lord Bell added: "I think she was beginning to wonder why she was still in hospital and what she was doing there and why she could not go home. So I do not think there is anything to worry about."
Three years ago Lady Thatcher was advised to refrain from making any more public speeches by doctors.
She spoke only briefly at her lavish 80th birthday festivities in October, attended by the Queen and Tony Blair.
On Tuesday, Lady Thatcher sent her congratulations to David Cameron, who has become the fifth Tory leader since her time in office.
On hearing of her illness, Mr Cameron said: "I was sorry to hear that Lady Thatcher is unwell. I wish her a full and speedy recovery."
She began to feel faint on a visit to the hairdressers and was taken to hospital by her bodyguards on Wednesday afternoon.
She was admitted to the Fulham Road hospital at about 1700 GMT.
A spokesman said that she had been sitting up in bed talking to people on Wednesday evening.
Daughter Carol - who is still in Australia having won the ITV1 show I'm a Celebrity, Get Me Out of Here - and her twin brother, Mark, who is also overseas, have both been informed.
Lady Thatcher served 11 years as prime minister before her ousting in 1990 - the longest period in the job in the 20th Century.
Her husband, Sir Denis Thatcher, died in June 2003, aged 88.