The Importance of Sleep for Your Health
Sleep is a naturally occurring process in which the “sleeper” is a state of reduced or absent consciousness. Sensory activity is relatively suspended and the voluntary muscles of the body are largely inactive. Although the individual sleeping has a decreased or inactive response to stimuli (depending on the degree), it is still not a state of hibernation or coma, which are both a much less active state. For instance, a quiet sound would not likely wake a sleeping individual. A loud sound probably would, but would not wake someone in a coma or a hibernating animal. Sleep is also easily reversible, waking up is easy with a relatively mild stimuli whereas hibernation and coma are not so easily recovered from.
Ironically, as sleep is a state of low activity in many respects, it is a time of heightened anabolic (growth and rejuvenation) activity. This is where the body ‘builds up’ the various systems of the body such as immune function, muscle growth and recovery, etc. This is the main reason that sleep is so important and why lack of it can be so debilitating. All mammals and birds sleep, but only some reptiles and even fish do.
How much sleep you need depends on your age as well as who you are. Obviously children need more sleep than adults because their bodies are growing so much. The need for sleep also varies among individuals. Some people do fine with four hours per night while most of us need about eight. Regardless, you can tell if you are getting enough sleep by how you feel during the day. If you experience daytime fatigue or dysfunction (without help from Starbucks), then you are getting enough sleep.
It seems that people who report sleeping 6-7 hours per night have the lowest death rate, but interestingly enough, those who sleep more than eight hours per night are more likely to die. This may seem like getting eight hours may be hazardous for your health, but those who sleep a lot also tend to be individuals with depression or low socioeconomic status (less access to health care, etc.).
Not getting enough sleep is hazardous for your health as is too much. The data is not in on why sleeping a lot is a problem, but it is thought to be related more to the type of people that sleep too much (depressed, low economic status, etc.) than to the sleep itself. However, too little sleep has been shown to double the risk of death by heart disease.
