More than 1 in every 5 Americans aged 18+ has been diagnosed with arthritis, the most common cause of disability today, says a CDC report Prevalence of Doctor-Diagnosed Arthritis and Arthritis-Attributable Activity Limitation – United States, 2007-2009 (MMWR). That is a total of 49.9 million people with arthritis in the USA. Arthritis is estimated to cost $128 billion every year. The report predicts that arthritis and arthritis-attributable activity limitation (AAAL) prevalence will continue to rise significantly over the next twenty years as people live longer. 21.1 million adults have been diagnosed with AAAL.

33.8% of obese females and 25.2% of obese males say they have been diagnosed with arthritis. The CDC informs that obesity prevention programs, as well as making physical activity more available have been shown to help bring down arthritis and AAAL rates.

The authors gathered data from the National Health Interview Survey (NHIS) 2007-2009, which involves face-to-face interviews with non-institutionalized individuals in the USA. Data was collected on people aged 18+.

The study found that:

  • 49.9 million (22.2%) American adults say they have been diagnosed with arthritis by a doctor.
  • Arthritis is much more common among older people
  • 24.3% of adult American women have been diagnosed with arthritis
  • 18.2% of adult American men have been diagnosed with arthritis
  • 21.9% of people who have less than a high school diploma have been diagnosed with arthritis
  • 20.5% of people with some college qualification have been diagnosed with arthritis
  • 29.6% of obese individuals have been diagnosed with arthritis compared to 19.8% among overweight people and 16.9% among people of normal weight or lower-than-normal weight.
  • 23.7% of people who regularly smoke have arthritis
  • 25.4% of people who used to smoke have arthritis
  • 19% of lifetime non-smokers have arthritis
  • Arthritis affects 18.7% of physically active people and 23.5% of physically inactive people

Arthritis prevalence is twice as high among obese adults as it is among adults of normal weight or lower-than-normal weight after adjusting for age.

Arthritis is a condition that affects the joints, part of the musculoskeletal system. In industrialized nations it is the principle cause of disability among individuals aged 50+.

In fact, arthritis is not in itself a single disease – the term covers more than 100 medical conditions. The most common form of arthritis is osteoarthritis, and it generally affects elderly patients. However, some types of arthritis can start at a very early age.

How does a joint work – a joint is the junction between two bones; where a bone moves on another bone. The two bones are held together by ligaments. Ligaments are like elastic bands, they keep the bones in place while the muscles relax or contract to make the joint move.

The surface of the bone is covered with cartilage. The cartilage stops the two bones from rubbing against each other. The covering of cartilage allows for the smooth and painless working of the joint.

A capsule surrounds the joint. The space within the joint – the joint cavity – has synovial fluid. Synovial fluid nourishes the joint and the cartilage. The synovial fluid is produced by the synovium (synovial membrane) which lines the joint cavity.

Arthritis occurs when something goes wrong with the joint; there could be a lack of fluid, the cartilage may be wearing away, the person’s body could be attacking good tissue (autoimmunity), or there may be an infection. There are many possible reasons why something might be wrong with the joint. What goes wrong depends on the type of arthritis the person has.

Examples of arthritis include:

  • Osteoarthritis – the cartilage becomes stiff, it loses its elasticity. This makes it more susceptible to damage. The cartilage shock absorber gradually wears away in some areas. The tendons and ligaments become stretched as the cartilage becomes damaged, causing pain. When the bones start rubbing against each other the pain can be severe.
  • Rheumatoid arthritis (RA) – the synovium (synovial membrane) is attacked, resulting in swelling and pain. RA is an inflammatory form of arthritis. Untreated RA can lead to deformity. RA is more common among females than males.
  • Infectious arthritis – the synovial fluid and tissues of a joint become infected. Most commonly this is caused by bacteria, but sometimes by fungi or viruses.
  • Juvenile rheumatoid arthritis (JRA) – the patient is aged 16 or less.

Click here to read about arthritis in more detail.

“Prevalence of Doctor-Diagnosed Arthritis and Arthritis-Attributable Activity Limitation -United States, 2007-2009”
Morbidity and Mortality Weekly Report (MMWR)
October 8, 2010 / 59(39);1261-1265

Written by Christian Nordqvist