Answers:
Various sleep disorders will do that including sleep apnea (I enjoy it). Some sleep "aids" resembling Ambien will also agree to you reckon you are asleep, but you may win up for hours during the darkness. My wife be an Ambien zombie until she stopped taking it.
Talk beside a sleep specialist.
8 hours is one and only a standard human average & opinion. Different inhabitants require differrent amounts of sleep and that can come and go depending on age as powerfully. For example, newborn sleep much much more than 2 year olds. Teenagers tend to call for more sleep as economically and elder adults recurrently involve smaller quantity. Your body also wishes to ambush up on sleep over time, so if you generally stipulation 8 hours, but solely bring 4 hours one darkness after over time your body will try to trademark up for the loss. Sleep want can also be difficult due to ailment, cold, flu, etc..
A lot of associates suffer from sleep apnea where on earth their airways collapse during sleep and they stop breathing for a few second.consequently they rouse up and friendly their airway to win a breath, after topple asleep again...over and over, sometimes 20, 30, 40 times a darkness...they dont realize theyre wake and sleeping, and when the alarm go bad they are exhausted and repeatedly decline unresponsive asleep during the daylight, which is terrifying if you drive or operate machinery. A sleep study may sustain to diagnose any sleep problems you might own, ask your doctor.