Quiet surroundings and dark curtains are important in getting a good day's sleep for those who work night shifts, a psychologist says.

Night workers who have trouble sleeping after their shifts shouldn't rely on sleeping pills, a German psychologist warns.

Hiltraut Paridon says there's a real danger of becoming psychologically dependent on the little chemical helpers.

A relaxing routine can be a healthy alternative.

"Whether it's drinking a cup of tea, reading the newspaper for a while or taking a shower, they've got to find out for themselves" what works best, says Paridon.

Quiet surroundings and dark curtains were important in getting a good day's sleep.

She warned that "shift work is never really healthy" and that "our bodies aren't meant to work nights".

While some people cope with the night shift better than others, no one should work nights for long periods, she said.

Many bodily functions follow a 24-hour rhythm.

The "sleep hormone" melatonin is released mainly at night, with peak sleepiness normally occurring between 2 and 4 am and alertness picking up again around dawn.

The circadian rhythm of people who work nights is disrupted.

"Many (night shift workers) suffer from sleep disorders. They have trouble falling asleep after their shift or are unable to stay asleep," said Paridon, noting that a number of medical conditions, including cardiovascular diseases and digestive problems, were associated with shift work.

"Shift workers generally have a less healthy diet, smoke more and get less exercise" than people who work during the day, Paridon said.

The deleterious effects of working nights are not only physical.

"Shift work impacts social contacts," pointed out Friedhelm Nachreiner, a psychology professor.

At worst, he said, night work can lead to social isolation because a shift worker's morning bedtime is when most other people start their day.

Shift workers should try to keep up with friends and family but they shouldn't overload the days they need to rest with work, such as building an extension of their house or running all of their errands on a single day.

"That's not only strenuous, but the risk of an accident increases enormously," Paridon said.

Copyright AAP 2014