Naproxen belongs to a group of medicines called non-steriodal anti-inflammatory drugs (NSAIDs),
which are used to reduce inflammation and pain in joints and muscles. 
Naproxen tablets are used to treat: 
Diseases of joints such as rheumatoid arthritis (including in children), osteoarthritis, ankylosing spondylitis. 
Naproxen cannot cure arthritis but is used to give relief of some symptoms such as inflammation, swelling, stiffness and joint pain
Attacks of gout 
Muscle and bone disorers 
Painful periods