Women experience far more terrifying nightmares than men, a study has found.

Their dreams are also more intense and leave more of an impression when they wake up, scientists say.

Psychologists say changes in a woman's body temperature - caused by her monthly cycle - are responsible for increasing the number of vivid and disturbing dreams.

Not such sweet dreams: Women experience far scarier nightmares than men because of changes in their body temperature, according to a study

The findings came from a study of 170 volunteers at the University of the West of England.

'We found that women reported significantly more nightmares than men,' said Dr Jennie Parker, who carried out the study.

When asked to record their most recent dream, 19 per cent of male students reported having a nightmare compared to 30 per cent of women.

The study, due to be published in a journal, also found that women's dreams were more emotional.

Dr Parker believes that nightmares help the brain 'rehearse' distressing and disturbing events that one is likely to encounter in the future.

'One of the things that people do is put all these dreams under the umbrella term nightmares,' she said.

'But there are different types of nightmares and women report more of them.'

Her work has identified at least three distinct types of nightmare, all of which may allow the brain to rehearse its reaction to a distressing or dangerous situation.

One involves being chased or hunted. Another involves the loss of a parent, child or partner. The third involves weird and new environments.

Past studies have linked changes in body temperature with dreams.

A woman's temperature usually rises after ovulation - half way through the monthly cycle --and falls again just before a period starts.

Dr Parker said there was evidence linking dreams to temperature changes in the menstrual cycle.

'Women who are premenstrual tend to dream more aggressively, and they are also more likely to remember the dreams,' she said.

Some dream experts argue that women don't have more nightmares but are simply better at remembering and talking about them.

However, the study asked volunteers to record all their dreams upon waking.

'It does look like women are experiencing more nightmares,' Dr Parker added.

Dr Chris Idikowski, director of the Edinburgh Sleep Centre, said there were significant differences in the way men and women dreamed.

'Women always remember dreams more than men,' he told the British Association science festival in Liverpool.

'They end up talking more about their mental life than men do so there's more ability to remember.'

Dreaming is part of the normal sleep pattern and happens every night, even for those who insist they don't dream.

Sleepers are most likely to remember nightmares and bad dreams if they wake up during them.