Is it real that I should sleep 8 hours bcuz I only sleep average 5.5 hours and does it really affect my health
As long as you take a full sleep on weekend and holidays, everything should be fine
Do you have sleep trouble everyday? If not, sleeping in less than 8 hrs is fine.
Sleeping is about quality, not quantity. If you sleep well, your heart is healthy too.
Maybe because it is difficult to measure the quality of sleep, one need 8 hrs sleep time a day. But if you feel rejuvinated and refreshed when you wake up, that's when you get a quality sleep