Musculoskeletal conditions (MSCs) are a group of diseases that affect the body’s bones, joints, muscles and the tissues that connect them. Common MSCs include back pain, rheumatoid arthritis, osteoarthritis, osteoporosis, and spinal disorders. 

MSCs are the most common cause of severe long term pain and physical disability in developed countries.1 They significantly affect the psychosocial wellbeing of individuals as well as their families and carers.2 They are responsible for substantial costs to the health and social care system and the economy.3 They are a leading cause of absence from work and lost productivity at work.2,3 MSCs comprise a diverse group of conditions. Some have a specific medical diagnosis (eg rheumatoid arthritis) but others have no clear medical diagnosis (eg back pain). 

Risk factors for the development and progression of MSCs include age, sex, family history, obesity, physical inactivity, injury and biomechanical occupational health issues. This briefing describes how many people have specific MSCs and how these numbers are expected to change between 2010 and 2020. This information will help us develop services where and when they are needed. 

The number of people with an MSC is called its population prevalence and population prevalence includes both clinically diagnosed and undiagnosed cases. We are only able to report national and sub-national rates of diagnosed MSCs. Undiagnosed cases are not included in our figures and so they are likely to be underestimates of the total number of people with these MSCs. 

Furthermore, the available data relate to specific MSCs such as arthritis or back pain and so do not include all MSCs.