Currently I am sleeping about 6 hours a day (or a bit less than that): from midnight to around 6 AM. I usually not feel sleepy after I wake up (and the neighborhood of where I just moved into is quite noisy every morning so that it is rather difficult for me to go back to sleep) so I usually get up right away.
I am afraid that I might not have had enough sleep each night (although I do not feel that much tired during the day) and that it might be harmful to me (in the long term) to sleep only around 6 hours a day. (Not sure if this is a relevant information: my age is 26.)
So is it really harmful for health (in any way) to sleep just around 6 hours (or less) a day? Is there any indication to tell if an individual gets enough sleep each day?