INSOMNIA

Insomnia is characterized by an inability to sleep and/or to be incapable of remaining asleep for a reasonable period. It is often caused by fear, stress, anxiety, medications, herbs, caffeine or sometimes for no apparent reason. An overactive mind or physical pain may also be causes. Poor sleep quality can occur as a result of sleep apnea or major depression. Poor sleep quality is caused by the individual not reaching stage 4 or delta sleep which has restorative properties. There are, however, people who are unable to achieve stage 4 sleep due to brain damage that still lead perfectly normal lives. (Source from wikipedia.org.)