India, Oct. 21 -- Sleeping at least 8 hours is time and again reiterated in the medical community. Since it is an essential building block required for the body's recovery, sleep is something you ideally shouldn't compromise on, even if it means pausing your favourite show on a cliffhanger and sleeping through the night to catch up on the next day.

But is sleeping 8 hours really sufficient? If that's the optimal mark for waking up refreshed, why do some people still end up feeling groggy? Is that even possible?

Turns out, it actually is. Addressing this, Dr Christopher J Allen, a physician in sleep medicine and pediatric neurology with 20 years in the medical field, shared in an October 20 Instagram post how 8 hours of sleep don't alway...