Sleep Cycles

Sleep Cycles last approximately 90 to 120 minutes in REM sleep cycles (rapid eye movement) and Non REM (non-rapid eye movement) Sleep Stages. In a normal sleep cycle REM sleep occurs every 90 minutes during the night, the first REM Sleep Cycle may last less than 10 minutes and the last REM Sleep Cycle may exceed 60 minutes. There are four Non REM stages in a Sleep Cycle that repeat throughout the night. The Sleep Cycle Stages are:

Non REM

• Stage 1 - A slow wave transition from wakefulness to sleep where eyes roll slightly and the brain waves slow in frequency to Alpha Waves (relaxed) which lasts only a few minutes until the next stage in the Sleep Cycle begins. You are still aware of your environment in this Sleep Cycle stage.
• Stage 2 - This stage in the Sleep Cycle is the beginning of actual sleep, the sleeper is less aware of their environment and the sleep cycle lasts about ten to twenty minutes.
• Stage 3 - This point in the Sleep Cycle is the beginning of a deep sleep. Some people experience Sleep Talking, Sleepwalking, Bed Wetting or Sleep Terror in this stage.
• Stage 4 - This stage in the Sleep Cycle is the deepest sleep. Your blood pressure has dropped and your muscles are completely relaxed. It is very difficult to wake someone in this stage of sleep, if they are awakened they will be extremely groggy and possibly unaware of their surroundings initially. The stage 4 sleep cycle is also when your body begins to recover from the day, it is very important to get adequate rest to fight off sickness and infections.

REM Sleep Cycle

• After 30 to 40 minutes of deep sleep you then ascend to the REM Sleep Cycle where you begin to retrace back to stages 3 and 2. Your nervous system becomes active increasing pulse, respiration and blood flow to the brain. With your eyes still closed your eyes begin to dart back and forth as if scanning around the room. You are not awake, this is the first stage of the REM Sleep Cycle. Dreaming may occur in all sleep cycles but in the REM sleep cycle dreaming is more emotional and more vivid than any other cycle.
• After the first REM sleep cycle you go back to Stage 2, Stage 3 and Stage 4 and then back to Stage 3 and Stage 2 then to the REM sleep cycle again. The Sleep Cycles will repeat throughout the night.