What Is Sleep And How Much Sleep Do I Need?

— -- Question: What is sleep and how much sleep do I need?

Answer: Sleep is a natural physiologic process, during which our mind and body rest. During the sleep, also, there is suspension of consciousness, as well as a reduction in our bodily movements. The exact function of sleep remains unclear. We do believe that it has a restorative type of function, during which there is regulation of hormones, for example, growth hormone is actually secreted during our sleep, specifically during slow-wave sleep, which is our deeper stage of sleep.

We also believe that sleep plays a role in our memory consolidation and processing. In addition, sleep probably also plays a role in buildup of protein and substances that are very important for our bodily functions, such as our immune system, our musculoskeletal system and our neurologic system.

We recommend that people obtain seven to eight hours of sleep. If you get any less than that, you're likely shortchanging yourself.

The reason I say that is if you get less than that seven to eight hours of sleep, there are both immediate and longer-term negative consequence.

The more immediate negative consequences are things like daytime sleepiness, drowsy driving -- during which you could hurt yourself or someone else, decrements in your neurocognitive function -- meaning you won't be able to focus or concentrate as you normally would, compromise in your vigilance ability and also, it can affect your relationship with your loved ones, because it affects your mood. It also has the potential to impact work performance.

Some of the longer-term consequences are things such as weight gain, insulin resistance -- which can be sometimes a precursor to diabetes, cardiovascular disease and even increased risk of death or increased mortality.