Osteoarthritis (OA) is a degenerative joint disease involving the cartilage and many of its surrounding tissues. Disease progression is usually slow but can ultimately lead to joint failure with pain and disability. OA of the hips and knees tends to cause the greatest burden to the population as pain and stiffness in these large weight-bearing joints often leads to significant disability requiring surgical intervention. The article reviews the existing data on epidemiology of osteoarthritis and the burden of the disease. Symptoms and radiographic changes are poorly correlated in OA. Established risk factors include obesity, local trauma and occupation. The burden of OA is physical, psychological and socioeconomic. Available data does not allow definite conclusion regarding the roles of nutrition, smoking and sarcopenia as risk factors for developing OA. Variable methods of diagnosing osteoarthritis have significantly influenced the comparability of the available literature. Further research is required to fully understand how OA affects an individual physically and psychologically, and to determine their healthcare need.