Many of us will occasionally experience days where we simply feel tired all day long. Usually this is caused by poor sleep the night before, an intense workout the previous day, or even symptoms of a cold or flu. The feelings of extreme fatigue are often remedied with a little rest during the day or some good old fashioned sleep the next night.
For some however, feeling tired and rundown during waking hours is an everyday occurrence. One that with continued lack of sleep can prove to be harmful to their health, and result in accidents or even death from dozing off at inappropriate times. While there are many possible causes of extreme daytime sleepiness including dietary deficiencies, depression, diabetes, anemia, or thyroid problems, chronic daytime fatigue can very likely be caused by a sleep disorder.