A mattress is a mat or pad, usually placed on top of a bed, upon which to sleep or lie.
The word mattress is derived from Arabic words meaning "to throw" and "place where something is thrown" or "mat, cushion." During the Crusades, Europeans adopted the Arabic method of sleeping on cushions thrown on the floor, and the word materas eventually descended into Middle English through the Romance languages.
Though a mattress may be placed directly on the floor, it is usually placed on top of a platform (such as a platform bed or a metal box-spring or a slatted foundation) to be further from the ground. Historically, mattresses have been filled with a variety of natural materials, including straw and feathers. Modern mattresses usually contain either an inner spring core or materials such as latex, viscoelastic, or other polyurethane-type foams. Mattresses may also be filled with air or water, or a variety of natural fibres, such as in futons.
Insomnia is a symptom which can accompany several sleep, medical and psychiatric disorders, characterized by persistent difficulty falling asleep and/or difficulty staying asleep. Insomnia is typically followed by functional impairment while awake.
Both organic and non-organic insomnia without other cause constitute a sleep disorder, primary insomnia. One definition of insomnia is "difficulties initiating and/or maintaining sleep, or nonrestorative sleep, associated with impairments of daytime functioning or marked distress for more than 1 month."
According to the United States Department of Health and Human Services in the year 2007, approximately 64 million Americans regularly suffer from insomnia each year. Insomnia is 41% more common in women than in men.