Rayner was born to Jewish parents in London, the eldest of four children. Her father was a tailor and her mother a housewife. Her father had adopted the surname Chetwynd, under which name she was educated at the City of London School for Girls. Her autobiography How Did I Get Here from There? was published in 2003, and revealed details of a childhood marred by physical and mental cruelty at the hands of her parents. After the family emigrated to Canada, in 1945 she was placed in a psychiatric hospital by her parents, and treated for 15 months for a thyroid defect.
Returning to the UK in 1951, Rayner trained as a nurse at the Royal Northern and Guy's Hospitals in London. She intended to become a doctor, however, while training as a nurse, she met actor Desmond Rayner, whom she married in 1957. The couple lived in London and Rayner worked as a midwife and later nursing sister.
Journalist and writer
Rayner wrote her first letter to Nursing Times in 1958, on nurses' pay and conditions. She then began regularly writing to the Daily Telegraph on themes of patient care or nurses’ pay. She began writing novels soon after her marriage, and by 1968 had published more than 25 books.
But the birth of her first child in 1960, meant that she found full-time nursing difficult, and so she focused on a full-time writing career. Initially writing articles for various magazines and publications, in 1968 she published one of the earliest sex manuals, People in Love, which brought her to national attention. Described as "explicit content," the same reviewer commended Rayner on her "down to earth approach to the subject."
By the 1970s, writing for Woman's Own Rayner had established herself as one of four new and direct Agony Aunts, alongside Marjorie Proops, Peggy Makins (aka Evelyn Home) at Woman and J. Firbank of Forum. Her advice in the teenaged girls' magazine Petticoat caused controversy. In 1972 she was accused of "encouraging masturbation and promiscuity in prepubescent girls". Her direct and frank approach led the BBC to ask her to be the first person on British pre-watershed television to demonstrate how to put on a condom, and she was one of the first people used by advertisers to promote sanitary towels.
The year after beginning to appear on Pebble Mill at One, Rayner started an agony column in The Sun in 1973, but left to join the Sunday Mirror in 1980, when she also made her second television series of Claire Rayner's Casebook. She left the Sunday Mirror shortly after the appointment of Eve Pollard as editor, and joined the Today newspaper for three years. Rayner was named medical journalist of the year in 1987.
Rayner became president of the Patients Association, and through her extensive charity work and writings was awarded an OBE in 1996 for services to women's issues and to health issues. Rayner had a very personal reason for supporting Sense's Older Person campaign, wearing hearing aids in both ears, and also had Age Related Dry Macular Degeneration, a sight loss common in older people.
Rayner was appointed to various UK Government committees on health, and resultantly was: the author of a chapter in The Future of the NHS (2006) edited by Dr. Michelle Tempest. Despite being President of the Patients Association Rayner used private health care. was a member of the Prime Minister's Commission on Nursing; the Labour government's Royal Commission on the Care of the Elderly. In 1999 Rayner was appointed to a committee responsible for reviewing the medical conditions at Holloway Prison, London, at the direction of Paul Boateng who was then the Minister for Prisons. The recommendations of this committee led to far reaching changes in the provision of medical care within Holloway.
A lifelong Labour Party supporter, she resigned in 2001 and joined the Liberal Democrats on fear of the proposed changes to the NHS from the administration of Prime Minister Tony Blair. She was also a prominent supporter of the British republican movement, although admitted her dual standards on accepting her OBE in 1996.
Rayner was Vice-President (and formerly President) of the British Humanist Association, a Distinguished Supporter of the Humanist Society of Scotland and an Honorary Associate of the National Secular Society. In the weeks leading up to her death, Rayner had the following to say about Pope Benedict XVI's state visit to the United Kingdom:
Rayner met her husband Desmond ("Des") Rayner at Maccabi in Hampstead; the couple married in 1957. They had three children together: writer and food critic Jay Rayner, BBC motoring journalist Adam Rayner and events manager Amanda Rayner.
Rayner was diagnosed with breast cancer in 2002 at the age of 71. She became a breast cancer activist in order to promote the work of the charity Cancer Research UK.
Rayner never recovered from emergency intestinal surgery she received in May 2010, and died in hospital on 11 October 2010. She told her relatives she wanted her last words to be: "Tell David Cameron that if he screws up my beloved NHS I'll come back and bloody haunt him."