Women who self-harm are significantly more likely to have been abused by their partner than those who do not, researchers have found.
A fifth of women say they have experienced domestic violence
They said it was possible self-harmers were more likely to become involved in abusive relationships.
But they said it was also possible being the victim of domestic violence led women to self-harm.
The Cambridge research found almost a fifth of both men and women attending A&E had experienced abuse.
Over 250 adults attending casualty at Addenbrooke's Hospital over a two-week period in 2001 were asked about their experiences of domestic violence and self harming, alcohol abuse and use of medical services.
Patients were asked questions ranging from if they had been seriously physically abused, if they had felt in fear of their lives to if they had been slapped.
Results from the study suggest women who self-harmed were 75 times more likely to report partner abuse than women who did not.
Men who self-harmed were over twice as likely to report partner abuse as those who did not.
But the researchers stress many factors may be involved in these estimates.
Based on the findings from what they admit is a small study, the authors estimate that among 55 000 patients attending casualty at any one hospital, around 500 would be there because they have been subjected to domestic violence.
But they say this is likely to be the tip of the iceberg.
Writing in the Emergency Medicine journal, they say: "There is evidence that many victims of domestic violence will not report it even if asked by a health professional."
Dr Adrian Boyle, who led the study, told BBC News Online: "We found a significant increased risk of physical or verbal abuse in women who self harmed."
He said A&E staff needed to be more aware of how many patients may be the victims of domestic violence.
Dr Boyle, who is currently preparing guidelines on how A&E departments should care for patients who have been abused at home, added: "We need to raise awareness that this is an important problem for our patients."