The condition of your bedroom is important. Lifestyle factors-age, physical activity, smoking, illness-are important. However, your mattress is the most important determiner of how you sleep. Your mattress should keep you supported and in one position all night, without the moving around that causes restless sleep and contributes to back pain. In fact, a good quality mattress can alleviate back pain (see Orthopedic FAQ.) Tossing and turning more, or waking up with aches in your arms, legs and back is a sure sign that your mattress is not comfortable. Your mattress may be a friend or an enemy to your body. Your body will let you know whether or not it has a problem with your mattress, so listen carefully.