Insomnia is characterized by an inability to initiate or maintain sleep. It may also take the form of early morning awakening in which the individual awakens several hours early and is unable to resume sleeping. Difficulty initiating or maintaining sleep may often manifest itself as excessive daytime sleepiness, which characteristically results in functional impairment throughout the day. Before arriving at a diagnosis of primary insomnia, the healthcare provider will rule out other potential causes, such as other sleep disorders, side effects of medications, substance abuse, depression, or other previously undetected illness. Chronic psychophysiological insomnia (or “learned” or “conditioned” insomnia) may result from a stressor combined with fear of being unable to sleep. Individuals with this condition may sleep better when not in their own beds. Health care providers may treat chronic insomnia with a combination of use of sedative-hypnotic or sedating antidepressant medications, along with behavioral techniques to promote regular sleep.