Insomnia, or not being able to sleep, is becoming a bigger problem according to experts. This is to do with our 24 hour lifestyles, not having to follow the natural rhythms of day and night but just going to bed when we feel like it. We also have a lot of artificial light, especially in cities, and spend a lot of time with electronic media which may stop us relaxing.
If you have trouble sleeping the first thing is to try and reduce these factors. You should have no smartphone, tablets or similar devices in the bedroom, and get the room as dark as possible, using blackout curtains if you can. It's better to have a typical time when you go to bed and stop watching TV a while before that, so you start to unwind. It's also better to avoid coffee and strong drinks in the evening, and not to eat a meal within a couple of hours of bedtime.