Studies claim to have found out that a person spends an average of 24 years of his life sleeping. Especially in the cold autumn and winter time we often feel tired. But where does this tiredness come from and what are the causes?

It is well known that newborns need much more sleep than adults – they sleep up to 16 hours a day, so they are tired permanently, so to speak. For us adults, 8 hours of sleep per day are usually enough, although these 8 hours are very often fallen short of. Tiredness is a sign of the body to make us understand that it needs rest and wants to be spared.

Tiredness is a consequence of lack of sleep. During sleep, the body is finally put into a kind of hibernation state in which only basic processes take place: Muscle activity, as we need it to stand upright, or seeing, are not needed during sleep. This state helps the body to regenerate itself and gain strength for the next day.

Sleep and fatigue are closely linked to a hormone of the pineal gland, or “epiphysis”. The pineal gland is located deep in the back of the brain and produces the hormone melatonin. However, melatonin is only released in the dark, i.e. when we are in dark rooms, or when – as in autumn – it gets darker outside more quickly.

The body knows that a high melatonin release means that night falls, tiredness sets in and you fall asleep. Around 3 a.m. the melatonin level finally reaches its maximum, in the morning hours the concentration decreases again. No wonder that we get tired more quickly in the dark winter months!

But also shift workers and frequent flyers (keyword: jet lag!) have to struggle with melatonin. After all, the body deliberately behaves completely asynchronously to the usual melatonin release. Besides melatonin, which is mainly responsible for fatigue and sleep, there are a number of other causes that can be responsible for excessive fatigue.