Domestic abuse is still hugely under-reported, with some victims not realising violence against them is a crime, says a new report.
In a new guide aimed at health professionals, the British Medical Association (BMA) warned there was an "unspoken epidemic" of domestic abuse.
It defines such abuse as physical violence as well as psychological, sexual and financial abuse.
Financial abuse can involve relatives or acquaintances targeting older people for money.
Domestic abuse has been reported to affect more than 350,000 people in England and Wales, with more than 45,000 incidents in one year in Scotland and more than 8,000 in Northern Ireland, the study said.
It called for doctors to receive better training so they can identify people at risk and ask appropriate questions.
Education programmes on domestic abuse should also be taught in primary and secondary schools, experts said.
The report, Domestic Abuse, produced by the BMA's Board of Science, said at least 750,000 children a year witness abuse.
Almost a third (30%) of domestic abuse begins in pregnancy, and it is just as common in homosexual relationships as heterosexual ones, it said.
The British Crime Survey has shown that, of women experiencing domestic abuse, only around half (51%) thought their worst incident was a crime. More than one in 10 (13%) said they thought it was "just something that happens".
