Kalvimalar

Research by the Lighting Research Centre at the Rensselaer Polytechnic Institute in New York State suggests light from laptop, tablet and smartphone screens tricks us into thinking it is daytime and keeps us alert, although this has been disputed.

In order to avoid insomnia, bedrooms should be a comfortable temperature (around 18C), quiet and well-ventilated, with comfortable beds and pillows, the Guardian reported.

Anything that stimulates the system like caffeine, alcohol, chocolate, tobacco, a heavy meal or strenuous exercise will make it harder to get to sleep, experts said.

For a proper sleep, indigestible foods are obviously best avoided since carbohydrates can promote serotonin, which aids sleep. Aim for a regular, balanced diet and no late-night excess, the report said.

Twenty minutes a day of exercise also will make a big difference to your sleep, but avoid it just before bed. A weekend lie-in or afternoon snooze can do more harm than good.

According to research at the University of Texas Southwestern Medical Centre, "sleep debt" is best "repaid" by getting up and going to bed at your normal times rather than disrupting your body clock.

Save sleep for bedtime as naps are recommended only if you are too exhausted to function.

According to Research at the University of British Columbia, every hour of sleep lost at night may cost us one IQ point the following day, and it is often a long-term issue.

To deal with their sleep problems without pills, most people focus first on what Colin Espie, professor of clinical psychology and director of the University of Glasgow Sleep Centre, calls "sleep hygiene" - our pre-bed routine, and the physical environment in which we try to sleep.

Espie believes these factors account for a mere 10 per cent of sleep problems: "most people with insomnia have better sleep hygiene than easy sleepers".