People who suffer with this sleep disorder experience excessive sleepiness during the day along having uncontrollable episodes of falling asleep. While it is considered a sleep disorder, it is also a chronic brain disorder where there is poor control of sleep-wake cycles. It can also cause weakness in the muscles. It takes most people about 90 minutes to reach the REM stage of sleep, but for those with narcolepsy, this stage of sleep is reached much more quickly. There is no known cause for this sleep disorder. Its symptoms include:
 

• Mental cloudiness and lack of energy

• Sudden loss of muscle tone

• Hallucinations

• Sleep paralysis
   

  This condition usually begins between the ages of 15 and 25. Symptoms can be somewhat managed by avoiding caffeine, alcohol, nicotine, and heavy meals. Scheduling daytime naps can also be helpful in reducing symptoms associated with narcolepsy.