What makes people fall asleep

There is this thing called sleep pressure. It is connected to our biological clock that makes sure we go to sleep at a certain time and feel well rested in the morning. Here is how sleep pressure works:

We’ve already seen that our sleep is partly regulated by our biological clock. But there’s a second mechanism that makes us drowsy — the homeostatic process, or for you and me, sleep pressure, that is the urge to sleep. It’s this process that makes you feel tired at the end of the day.

Slowly but surely, the pressure increases…

The homeostatic process determines this urge to sleep, which varies depending on how you long you’ve been awake and how much energy you’ve used during the day. The longer we’re awake, the more the urge to go to sleep builds.

It needs to be at a certain level in order for you to fall asleep. A lot of insomniacs forget this — they try to go to sleep earlier in the hope that they’ll finally get to sleep that way… However, as they’re not tired enough, they fidget and struggle to fall asleep. Sleep doctors often encourage insomniacs to push back their bedtime, even if they end up having a really short night’s sleep. How come? So that the urge to sleep builds and they get used to the feeling — and hopefully manage it differently next time.