London  - Former British Prime Minister Margaret Thatcher was being kept in hospital in London Sunday after breaking her arm in a fall at her London home on Friday.

The 83-year-old "Iron Lady" was in good spirits according to her son, Mark, on Saturday, but a decision on when to allow her out was being left to doctors.

Thatcher had "tripped over at home" early Friday and broken a bone in her upper arm. She was taken to Chelsea & Westminster hospital in central London.

Thatcher, who left office in 1990, has suffered a number of heath scares over recent years, including a string of minor strokes.

Last summer, her daughter Carol spoke for the first time publicly about the ex-premier's battle with dementia.

She said her mother did now struggle to finish sentences, did not know where she lived and even forgot that her husband Denis was dead. (dpa)