There are two basic types of sleep. R.E.M. (Rapid Eye Movement) sleep is the dream state where brain waves are similar to being awake. Non REM sleep is where we spend most of our sleep time and it has 3 stages. Stage 1 is the transition of being awake to going into a deeper sleep. Stage 2 is true sleep which alternates with R.E.M. sleep.  Stage 3 is a very deep sleep. The average person needs 7 to 9 hours of sleep.

Sleep apnea is important since over a period of time it can actually damage the heart muscles. Sleep apnea is a pause or stopping of breathing during sleep either related to an obstruction in the upper airway or a problem with the brain not sending the proper signals to the lungs. Narcolepsy is the excessive daytime sleepiness with disturbed nocturnal sleep pattern.

Treatment of sleep disorders includes sleep hygiene which involves avoiding caffeine, alcohol, nicotine and exercise prior to sleep. Medication can also help with sleeping disorders.