A mattress is a large pad designed to support a reclining body. Mattresses are used either as or on a bed. Mattresses may consist of a quilted or similarly fastened case, usually of heavy cloth, that contains hair, straw, cotton, foam rubber, etc., or a framework of metal springs. Mattresses are placed on top of a bed base which may be solid. Proper mattress is essential for a good night sleep and to avoid back pain.