“The needed sleep duration is individually different and is between five and ten hours per night.”
While most people would have approximately a seven to eight hours sleep, there are people who sleep short and people who sleep long.
However, you should make sure that you don’t sleep less than five hours on average. A healthy sleep can not be measured on its duration, but only as to whether you feel good during the day and your capacity right.
It is quite natural that you sleep with increasing age fewer and shorter depth. This can be the case with men from the 40th age and with women from the 50th.
So you need not worry if you go to bed already at 21 o’clock in the evening and awaken at 3 o’clock. These six hours of sleep can be quite sufficient.
Maybe try to go to bed a little later, so that you are not already awake in the middle of the night.