The mattress you choose to sleep on has a tangible effect on your ability to sleep soundly. A poorly constructed mattress can cause back and neck pain. After your mattress has sustained fifteen or twenty thousand hours of sleep, it loses support and structure. Your sleeping position (front, side, or on your back) also correlates with certain areas of body pain. For example, sleeping on your stomach causes back pain, since you are putting undue strain on your back. Individuals with conditions, such as arthritis, will want to take that into consideration when shopping for mattresses.