Children and pensioners were among more than 2,000 people who attended A&E departments in Preston, Chorley, Blackpool, Lancaster and Southport over three years with injuries from being assaulted in the home.
The data is from a report called Assaults in the Home across Lancashire, which was collected by the Trauma and Injury Intelligence Group (TIIG) between 2011 to 2014, and is thought to be the most recently available.
The report is based on incidents recorded by accident and emergency departments across Lancashire to determine the level of assault-related injuries suffered in the home, and was collated to help local organisations tackle the issue.
It points out not all incidents of domestic violence are reported to the police.
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These already disturbing figures are feared to be the tip of a much bigger iceberg, according to Philippa Olive, who is a senior research fellow in gender-based violence, and health systems responses, for Lancashire Teaching Hospitals and UCLan.
She said: “The number reported is large, troubling and significant – and is also likely to be a significant underestimate.
“Not all attendances may not have location, i.e. the home, recorded.
“And only a small proportion of people subjected to domestic violence go to A&E.
“The data is quite complex and has a number of limitations.
“Whereas we are more familiar with partner on partner violence we also see some children are subjected to to direct violence, whether by parent to child or siblings.
“We see a whole range of injuries.”
There were 2,354 attendances at A&Es across Lancashire due to assault injuries in the home between 2011 and 2014.
Seven of the victims were little girls aged four and under, and 13 were boys aged four or under.
Nine other victims were boys aged between five and nine.
At the other end of the spectrum, 24 elderly ladies or over attended hospital with domestic injuries and 14 men aged over 75 were also recorded in the report.
The figures show over half – 52 per cent – of the admissions were boys or men.
Four hundred and ninety-five (more than a fifth) were people from Preston and 771 – more than a third – were from Blackpool.
Royal Preston Hospital has 28% of the admissions while Blackpool Victoria Hospital had 47%.
Philippa added: “I think it’s really important to recognise there is a huge health burden associated with domestic assaults and sexual violence, not just to hospitals but to society as a whole.
“One research project concluded there was a cost of £26bn in 2012 in the UK.
“Help is very much available – there are specialist leads at the trust and they work really closely with local domestic violence services. There are increasingly closer relationships between specialist services and local hospital departments”
Hospitals in the county offer domestic violence support to all patients and ward staff receive training regarding safeguarding and how to spot somebody who may be at risk.