is a sleep disorder in which the symptoms are difficulty getting to sleep, difficulty staying asleep, and difficulty getting restful sleep.

are drugs that are used to reduce general arousal and thus facilitate sleep.

is the amount of time it takes for half a dose of a drug to be eliminated from the body.

is the return of symptoms such as sleep problems that can occur when a person stops taking a drug.

is a sleep disorder characterized by excessive sleepiness.

is a sleep disorder characterized by daily irresistible attacks of sleep.

is a brief cessation of breathing that causes a reduction of oxygen intake that wakes a sleeping individual.

is a sleep disorder characterized by repeated awakenings caused by frightening dreams.

is a sleep disorder characterized by the abrupt awakening from sleep with a panicky scream.

is a sleep disorder in which sleep is frequently disrupted because of problems with breathing.