Former teacher Rebecca Morgan-Jones felt her workload had been too much
Teachers are facing a constant battle to maintain the discipline and respect of their classes, according to practitioners in the profession.
The issue has been put in the spotlight by the case of teacher Peter Harvey, who attacked a boy with a metal weight after pupils began to misbehave during a lesson at All Saints' Roman Catholic School, Mansfield, in July 2009.
Mr Harvey was cleared at Nottingham Crown Court of attempted murder and grievous bodily harm with intent but admitted grievous bodily harm.
The court heard he had taken time off with depression and stress but was mocked by pupils in the moments before the attack.
Professional bodies and teachers themselves have warned the pressures of keeping order in a classroom and workload are causing increasing problems.
Rebecca Morgan-Jones was head of Art at Toot Hill secondary school in Bingham, Nottinghamshire, but after taking a year off is currently in a non-teaching role.
"I lost my confidence," she said. "I thought just stepping back into the classroom would have been quite a daunting experience.
"It is the pace of the day, that was the biggest stress for me.
"We would arrive at half seven or eight and you would be here 'til half five or six and it's the pace at which you have to work and the amount of work you have to produce in the day."
Chris Eardley, a science teacher at Toot Hill, felt the stress could come from different areas.
"When I first started teaching I was in a different school and it was certainly the pressure of going in front of a class and I found it might be a class where their behaviour might be quite challenging.
"Pupils - if they see a weakness they will attack it and then it can be very hard, as many teachers find out in their first year, it can be very hard to come back from that."
A study by the Schools Advisory Service, the largest independent provider of teacher absence insurance in the UK, showed that in one year, one in three teachers took sick leave as a result of work-related stress.
Research for the Teacher Support Network found the main causes of stress were excessive workload, aggression from pupils and parents and pressure from inspections.
Julian Stanley, chief executive of the Teacher Support Network, said: "The statistics for sickness absence in teaching are higher than in any other career so there is certainly an issue about culture, about changing it so that people can share their difficulties and actually we support people in a more effective way.
"Stress, ill health, pressure anxiety - all these things are commonplace in what is a fabulous profession, a unique but very challenging profession."
Mick Brookes, General Secretary of the National Association of Head Teachers, said a lack of discipline and respect had a huge effect on schools.
"That is extremely trying and extremely wearying and it does put some people into a very bad place.
"I can think of some of my colleagues who have just been unable to face a classroom.
"Having to deal with - sometimes low level - disruption in class when you are engaged in trying to raise standards of learning, to have that sabotaged by groups of children day after day, it takes its toll."