We need to sleep to allow our bodies time to repair. Most people need around eight hours sleep a night, with younger people needing more and older people less.

Every so often we may have a bad night’s sleep but this doesn't do us any harm (it just makes us feel very tired the next day).

If you don’t sleep, or have very poor sleep for several nights, you will find it hard to concentrate and make decisions, you will feel exhausted and may even start dropping off during the day - just like your grandparents! If it goes on for some time you could even start to become depressed.

Lack of sleep can also make you more vulnerable to suffering from high blood pressure, diabetes and obesity.

Top tips on how to get a good night's sleep

• Go to bed at the same time - It helps if you have a routine and it's important that you go to sleep at night when you feel tired.
• Get up when you wake up - If you are awake before your alarm then it's better to get up instead of worrying that you can't go back to sleep. 
• Keep fit - Regular exercise reduces sleep-stopping adrenaline.
• Eat sensibly - Avoid eating last thing at night or going to bed hungry.
• Your bed - For a good night's sleep a firm, level and supported mattress helps.
• Room temperature - Sleep is best with room temperature between 15 -21 degrees celsius so make sure you aren't too hot or too cold.
• Night clothes - Wear loose-fitting cotton night garments to allow your skin to breathe. If you sleep naked then you don't have to worry about this!
• Relax before bedtime - Herbal remedies can help reduce stress and get you into the right mind frame. Avoid caffeine as this will keep you awake.

If you aren't able to sleep night after night then it might be worth speaking to your doctor.

More...

The BBC Sleep pages have more information on sleep.