Patients are becoming increasingly abusive as their expectations of the NHS rise, doctors' leaders said yesterday.

A survey published by the British Medical Association showed that one in 12 doctors had been assaulted in the past year and one in three had been sworn at or shouted at. The violence ranged from being pushed to being attacked with a weapon. One in 35 had suffered a minor injury and one in 180 had been seriously injured.

Accident and emergency specialists, who see many patients who have been drinking or taking drugs, were at highest risk of being physically attacked, the survey found.

The postal questionnaire was sent to 3,000 GPs and hospital doctors of whom 890 responded. The BMA said all frontline staff should be taught how to defuse potentially violent situations and how to restrain aggressive patients.

One GP described how, in the middle of a consultation a patient jumped up, locked the door and said he was going to kill the doctor. The panic button didn't work and the phone lines to reception and the practice manager were engaged. He was unable to summon assistance for 25 minutes.

An A&E doctor responding to the survey wrote: "When people are frustrated after waiting for a service, or the service does not meet their expectations, it is only human nature to be angry.

"Add to this a few pints of intoxicating liquid and what do you expect?"

James Johnson, chairman of the BMA, said the findings were shocking. "A significant number of respondents asked if verbal abuse counted. Of course it counts - if they have to ask it shows how much verbal abuse is tolerated."

He added: "We can all understand patients becoming frustrated but that is never an excuse for violent behaviour - especially at people who are trying to help them."