Violent and abusive patients are costing the NHS more than £100m a year, according to a Panorama investigation.
An estimated 75,000 staff were attacked last year, costing the NHS in extra security, absenteeism, training of staff and legal bills, it reports.
The BBC One show collaborated with hospitals in Birmingham and Edinburgh to expose some examples of the abuse.
The body in charge of NHS security in England said money was being spent "effectively" and violence was falling.
Panorama calculated that between 2005-2006 the NHS spent £100m dealing with violence and abuse. In Scotland the cost was more than £3m.
The programme contacted health authorities across the UK to assess how much was being spent on security, such as CCTV and personal alarms for staff; training staff to deal with violence and aggression; absenteeism resulting from violence; and pursuing offences through the courts.
It discovered the cost was equivalent to the salaries of 4,500 nurses or more than 800,000 paramedic call-outs.
Reporter Shelley Jofre spent nine months at two of the UK's busiest hospitals - Heartlands in Birmingham and the Royal Infirmary in Edinburgh - to uncover some examples of the abuse.
She said: "In a single week at Heartlands, for example, I heard about a nurse being punched in the chest, a doctor being punched in the head and another having a chair thrown at him - all by patients they were trying to help."
But despite the government and the NHS's zero tolerance policy towards violence against staff, the programme found that fewer than 2% of attacks on staff result in prosecutions.
And staff say much of the abuse is often not reported.
A senior consultant at Heartlands Hospital, Tony Bleetman, who is in charge of workers' conflict training, said staff were reluctant to report abuse because they did not feel anything would be done.
"I am absolutely clear that official figures are the very small tip of a very large iceberg," he said.
Footage also shows NHS staff and police dealing with a violent patient
Amai Gold, a nurse who was left permanently disabled after a patient stabbed her with a needle, told the programme how she had her case dropped after a two-and-a-half-year struggle to get it to court.
The programme shows CCTV footage of a number of incidents of violence and also highlights the case of convicted rapist and kidney dialysis patient Donald Gibson, who was sentenced to nine months in prison for abusing nursing staff at Edinburgh Royal Infirmary.
The hospital had to spend £42,000 on security measures last year because of his abusive behaviour.
The spokesman for the NHS Security Management Service, responsible for the management of security in England, said there had been a reduction in violence against NHS staff and an increase in prosecutions of those who assault them.
Around 250,000 members of staff had so far received specialist training to deal with abuse and money was being spent "effectively and wisely", he said.
He added: "Few would begrudge NHS staff the resources that are spent on helping to protect them from violence."
Panorama: GBH on the NHS can be seen on BBC One at 2030 GMT on Monday 26 February