More than a third of all women worldwide – 35.6% – will experience physical or sexual violence in their lifetime, usually from a male partner, according to the first comprehensive study of its kind from the World Health Organisation (WHO).

The report reveals the shocking extent of attacks on women from the men with whom they share their lives, with 30% of women being attacked by partners. It also finds that a large proportion of murders of women – 38% – are carried out by intimate partners.

"These findings send a powerful message that violence against women is a global health problem of epidemic proportions," said Dr Margaret Chan, director general of the WHO. "We also see that the world's health systems can and must do more for women who experience violence."

The highest levels of violence against women are in Africa, where nearly half of all women – 45.6% – will suffer physical or sexual violence. In low- and middle-income Europe, the proportion is 27.2%. Yet wealthier nations are not necessarily always safer for women – a third of women in high-income countries (32.7%) will experience violence at some stage in their life.

Of the women who suffer violence, 42% sustain injuries, which can bring them to the attention of healthcare staff. That, says the report, is often the first opportunity for violence in the home to be detected and for the woman to be offered help.

Chart depicting violence against women worldwide

Violence has a profound effect on women's health. Some arrive at hospital with broken bones, while others suffer pregnancy-related complications and mental illness.

The two reports from the WHO – one on the prevalence of violence, the other offering guidelines to healthcare staff on helping women – are the work of Dr Claudia Garcia-Moreno, lead specialist in gender, reproductive rights, sexual health and adolescence at WHO, and Professor Charlotte Watts, an epidemiologist who specialises in gender, violence and health from the London School of Hygiene and Tropical Medicine.

"For the first time we have compared data from all over the world on the magnitude of partner violence and sexual violence by non-partners and the impact of these sorts of violence on health," said Garcia-Moreno. These included HIV and other sexually transmitted infections, depression, women turning to alcohol, unwanted pregnancies and low-birthweight babies.

There were variations in the rates of violence against women in different regions of the world but, said Garcia-Moreno, "in whatever region we looked at, it is unacceptably high".

Even in high-income countries, 23.2% of women will suffer physical and/or sexual violence from a partner in their lives, their data from 81 countries shows. The global figure for women attacked by partners was 30%.

More sexual assaults and rapes by acquaintances or strangers are reported in high-income countries than elsewhere – the report says that 12.6% of women in wealthy countries will be sexually attacked by a non-partner in their life, which is higher than the African rate of 11.9%. But the data on such crimes is not well collected in all regions.

The authors say that their previous research shows that better-educated women are less likely to suffer violence, as are those who have jobs, although not in all regions.

There is a need to tackle social norms, said Watts. "What are society's attitudes concerning the acceptability of certain forms of violence against women?" she asked. "In some societies it is not OK – but not all."

"I think the numbers are a wake-up call for all of us to pay more attention to this issue," said Garcia-Moreno. Over the past decade there had been increasing recognition of the problem, she said, but "one has to recognise that it is a complex problem. We don't have a vaccine or a pill".

The new WHO clinical and policy guidelines recommend training for healthcare staff in recognising the signs of domestic violence and sexual assault, but they rule out general screening – there is not a case for asking every woman who arrives in a clinic whether she has been subjected to violence.

"But if you see a woman coming back several times with undisclosed injuries, you should be asking about domestic violence," said Garcia-Moreno. "When I was training in medical school, it wasn't something you learned or knew about. Years later, I was sometimes in a situation where I could tell there was something else going on in the woman I was interviewing, but didn't have any sense that domestic violence was the issue. Now I think I would handle the interview very differently."