Five stages of Sleep.

  • Stage 1 - light sleep, eyes move slowly, and muscle activity slows. This stage forms 4-5% of total sleep.
  • Stage 2 - eye movement stops and brain waves become slower, with occasional bursts of rapid waves called sleep spindles. This stage forms 45-55% of total sleep.
  • Stage 3 - extremely slow brain waves called delta waves begin to appear, interspersed with smaller, faster waves. 4-6% of total sleep
  • Stage 4 - the brain produces delta waves almost exclusively. It is very difficult to wake someone during stages 3 and 4, which together are called "deep sleep.
  • There is no eye movement or muscle activity.
  • People awakened while in deep sleep do not adjust immediately and often feel groggy and disoriented for several minutes after they wake up.Forms 12-15% of sleep
  • Stage 5 - REM - breathing becomes more rapid, irregular and shallow, eyes jerk rapidly in various directions, and limb muscles become temporarily paralyzed.
  • Heart rate increases, blood pressure rises, and males develop penile erections.
  • When people awaken during REM sleep, they often describe bizarre and illogical tales - dreams. Forms 20-25% of total sleep time.

Don't forget to share this pointer!

View more comments +