Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Insomnia is defined as difficulty initiating or maintaining
sleep, or both,
despite adequate opportunity and time to sleep, leading to impaired daytime
functioning. Insomnia may be due to poor quality and/or quantity of sleep.
Insomnia is very common and occurs in 90% of the general population has
experienced acute insomnia at least once.
Approximately 10% of the population may suffer from chronic (long-standing)
Insomnia affects people of all ages including children, although it is more
common in adults and its frequency increases with age. In general, women are
affected more frequently than men.
Insomnia may be divided into three classes based on the
duration of symptoms.
Insomnia lasting one week or less may be termed transient
short-term insomnia lasts more than one week but resolves in less
than three weeks; and
long-term or chronic insomnia lasts more than three weeks.
Insomnia can also be classified based on the underlying reasons for insomnia
such as sleep hygiene, medical conditions, sleep disorders,
stress factors, and so on.
It is important to make a distinction between insomnia
and other similar terminology; short duration sleep and sleep deprivation.
duration sleep may be normal in some individuals who may require less time for
sleep without feeling daytime impairment, the central symptom in the definition
In insomnia, adequate time and opportunity for sleep is available,
whereas in sleep deprivation, lack of sleep is due to lack of opportunity or
time to sleep because of voluntary or intentional avoidance of sleep.
Insomnia is the perception of inadequate or poor-quality sleep. It can be due to problems falling asleep, early wakening, waking frequently during the night, unrefreshing sleep, or a combination of these. Contrary to some popular beliefs, insomnia is not defined by the total amount of sleep one gets or how long it takes a person to fall asleep. Individuals can vary in their need for sleep, and in the time required to fall asleep. What is a refreshing night's sleep for one person might be insomnia for another person.