Arthritis Osteoarthritis 10 Surprising Facts About Osteoarthritis Where it strikes, sex differences, reducing your risk, and more By Carol Eustice Updated on September 17, 2022 Medically reviewed by Scott Zashin, MD Print Jeannot Olivet/E+/Getty Images Table of Contents View All Table of Contents Common Form Types of OA Common Joints Sex Differences Mortality Risk Cause of Disability Reducing Your Risk Genetics and OA Imaging Findings Overall Health Osteoarthritis (OA) is often called "wear and tear" arthritis. It used to be considered just a consequence of aging. But now, researchers know it's a more complex disease process than that. OA develops when the cartilage inside a joint breaks down. (Cartilage helps bones glide over each other.) This article will look at some important information you may not know about osteoarthritis. This includes what kinds there are, where it most often strikes, who gets OA, and even how it can lead to death. Most Common Form of Arthritis Although there are more than 100 types of arthritis, OA is the most common. OA affects more than 32.5 million, or 1 in 7, adults in the U.S. Unlike many forms of arthritis, OA is not an autoimmune disease. It's considered a degenerative disease. ARTHRITIS TYPE U.S. PREVALENCE Osteoarthritis 32.5 million Gout 8.3 million Psoriatic Arthritis 2.25 million Rheumatoid Arthritis 1.5 million Ankylosing Spondylitis 1 million Juvenile Arthritis 300,000 Source: Arthritis National Research Foundation Types of Osteoarthritis The two main types of osteoarthritis are defined by what causes the condition. Primary OA has no known underlying cause or genetic predisposition. It's sometimes called idiopathic OA.Secondary OA is caused by another medical condition or trauma to the joint such as a sports injury or repetitive use. Medical conditions that can lead to secondary OA include: Rheumatoid arthritis (RA) Psoriatic arthritis Gout Infectious arthritis Genetic joint disorders (Ehlers-Danlos syndrome) What is Generalized Osteoarthritis? Most Commonly Affected Joints OA can affect any joint. It's more common in the ones that are used more and are prone to injuries or repetitive stress trauma. The joints that are most commonly involved in OA are: Knees Hips Hands Feet and ankles Back and neck Knee OA is the most common. It's estimated to affect at least 19% of Americans over 45. Every year in the U.S., doctors perform a million OA-related joint-replacement surgeries on knees and hips alone. What Are Autoimmune Diseases? Recap About 32.5 million Americans have osteoarthritis. It's the most common form and can be primary or secondary to conditions like RA and gout.The most commonly affected joints are the knees, hips, hands, feet and ankles, and back and neck. Sex Differences The sex you were assigned at birth makes a difference in your OA risk. While both males and females get OA, the prevalence is higher in females. Research shows that roughly 60% of people with OA are female. Females are also 40% more likely to develop knee OA than males. Until age 45, OA is more common in males. However, after the age of 45, the disease is more common in females. After age 60, the prevalence of OA is approximately 10% in males and 13% in females. Research suggests that the differences may be due to: Fluctuations of female hormonesA tendency for females to carry more weightDifferent ways of moving lead to greater joint strainDifferences in the musculoskeletal symptom (e.g., less knee cartilage than males) Osteoarthritis and Mortality Risk You usually don't think of arthritis as a killer disease. But osteoarthritis is associated with an increased risk of death from: Cardiovascular diseaseDiabetesKidney disease An estimated 500 deaths per year are directly attributed to OA-related factors. And that number may be too low. OA's true contribution to mortality is hard to judge. For example, deaths from complications due to NSAID use aren't counted, even though they can cause OA-related kidney disease. It may be that pain from OA leads to less exercise and movement, which contributes to weight gain. Higher weight is linked to heart disease and diabetes. Even so, there's no evidence that OA, on its own, shortens your life span. One 2019 study even reported a longer life span in people with OA. Major Cause of Disability Many people find themselves sidelined when they develop knee osteoarthritis. It's among the leading causes of disability in people over 60. About 80% of people with OA have a limited range of motion. About 25% cannot perform activities of daily living. 30% say it's hard to stoop, bend, or kneel 20% have trouble walking three blocks or handling large objects Statistics from 2015 show that people with knee osteoarthritis missed about 10 days of work that year, compared to the average person's 7.5 missed days. Working-age people with OA are unemployed more often than people without OA. This is likely because of OA-related limitations. Will Osteoarthritis Get Worse? Reducing Your Risk Risk factors for developing osteoarthritis include: Age: OA is most common after age 40.Hormones: Menopause changes appear tied to OA.Previous injury: Trauma to a joint increases its risk.Other conditions: RA, gout, and several other disorders contribute to cartilage wear.Genetics: OA runs in families and is believed to involve a genetic component. If you're high risk and want to lower your odds of developing OA, or if you want to slow it down, you have several options: Managing your weight Avoiding joint injury Getting regular physical activity Controlling blood sugar Choosing a healthy diet Not smoking Getting enough sleep Managing stress How Osteoarthritis Is Treated Genetics and OA OA is believed to have a genetic component. Researchers say about 20% to 35% of knee OA and between 40% and 80% of hip and hand OA may be determined by genetics. So far, 90 locations on the human genome have been linked to the development of OA. More important, though, are changes in gene expression (epigenetics) that happen throughout your life. Ancestry and ethnicity play a role as well: Black Americans are the most likely to have symptomatic knee OA.Hip OA is lower in people with Asian heritage. Imaging Findings Not everyone with evidence of OA on imaging tests has symptoms. For example, about 80% of people over age 55 have X-ray evidence of osteoarthritis. But only about 60% of them have symptoms. The degree of damage visible on an X-ray isn't always relevant either. X-rays don't detect early cartilage damage. Sometimes a person with severe pain has minimal findings. X-rays do show: Narrowed space between joints, where cartilage has worn awayBone spurs, which are common in degenerating jointIncreased bone density (subchondral sclerosis), which is often found around narrowed joint spaces The Pathophysiology of Osteoarthritis Affects Overall Health Osteoarthritis is often not the only health problem someone has. Approximately 40% of adults diagnosed with knee OA report that their health is either poor or fair. Fall-related injuries can have a major impact on health. In one study, more than 50% of people with knee OA said they'd fallen in the previous year. Researchers found a worse health-related quality of life in people with knee OA and a history of falling than in other groups. The CDC says one in five falls leads to a serious injury. Falls can cause broken bones and head injuries. They're especially dangerous for someone taking blood thinners. Signs and Symptoms of Osteoarthritis Summary OA is the most common form of arthritis. It can be primary or secondary. The knees, hips, and hands are most often affected. Those who are female at birth are more likely to have OA. About 500 OA-related deaths are reported each year. People with OA are at increased risk of death from diabetes and heart or kidney disease. OA is a major cause of disability. It's linked to absenteeism and unemployment. You can lower your OA risk by managing weight, protecting joints, and living a healthy lifestyle. Genetics make up a large portion of your OA risk. Black people are most likely to have symptomatic knee OA. Asians have a lower rate of hip OA. X-rays may show very little damage in someone with severe pain or severe damage in someone with no symptoms. OA impacts your overall health. Fall risk is high and falling can result in serious injuries. A Word From Verywell Osteoarthritis is a serious condition that can have very real impacts on your life and health. The good news is that researchers have learned a lot about it and that's led to better treatments. More than ever, you have treatment options that can help you stay mobile and active, minimize pain, and keep you enjoying life. 21 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. United States Bone and Joint Initiative. The Burden of Musculoskeletal Diseases in The United States (BMUS), Fourth Edition. Cleveland Clinic. Osteoarthritis. Osteoarthritis Research Society International. Which joints does osteoarthritis affect? Wallace IJ, Worthington S, Felson DT, et al. Knee osteoarthritis has doubled in prevalence since the mid-20th century. Proc Natl Acad Sci U S A. 2017;114(35):9332-9336. doi:10.1073/pnas.1703856114 Osteoarthritis Action Alliance. OA prevalence and burden. Losina E, Weinstein AM, Reichmann WM, et al. Lifetime risk and age at diagnosis of symptomatic knee osteoarthritis in the US. Arthritis Care Res (Hoboken). 2013;65(5):703-711. doi:10.1002/acr.21898 Zhang Y, Jordan JM. Epidemiology of osteoarthritis [published correction appears in Clin Geriatr Med. 2013 May;29(2):ix]. Clin Geriatr Med. 2010;26(3):355-369. doi:10.1016/j.cger.2010.03.001 Mayburd AL, Baranova A. Increased lifespan, decreased mortality, and delayed cognitive decline in osteoarthritis. Sci Rep. 2019;9(1):18639. doi:10.1038/s41598-019-54867-8 Yucesoy B, Charles LE, Baker B, Burchfiel CM. Occupational and genetic risk factors for osteoarthritis: a review. Work. 2015;50(2):261-273. doi:10.3233/WOR-131739 Chio CC, Siu MK, Tai YT, et al. Renal insufficiency plays a crucial association factor in severe knee osteoarthritis-induced pain in patients with total knee replacement: A retrospective study. Medicine (Baltimore). 2020;99(6):e19125. doi:10.1097/MD.0000000000019125 Osteoarthritis Action Alliance. Diabetes and heart disease: How does arthritis play a role? Primorac D, Molnar V, Rod E, et al. Knee osteoarthritis: A review of pathogenesis and state-of-the-art non-operative therapeutic considerations. Genes (Basel). 2020;11(8):854. doi:10.3390/genes11080854 Neogi T. The epidemiology and impact of pain in osteoarthritis. Osteoarthritis Cartilage. 2013;21(9):1145-1153. doi:10.1016/j.joca.2013.03.018 Menon J. Osteoarthritis related absenteeism and activity limitations. Osteoarthritis Cartilage. 2015;23(2):A343. doi:10.1016/j.joca.2015.02.629 Mahajan A, Patni R. Menopause and osteoarthritis: Any association? J Midlife Health. 2018;9(4):171–172. doi:10.4103/jmh.JMH_157_18 Punzi L, Galoozi R, Luisetto R, et al. Post-traumatic arthritis: overview on pathogenic mechanisms and role of inflammation. RMD Open. 2016;2(2):e000279. doi:10.1136/rmdopen-2016-000279 Centers for Disease Control and Prevention. Osteoarthritis. Arthritis Foundation. Slowing osteoarthritis progression. Chen D, Shen J, Zhao W, et al. Osteoarthritis: toward a comprehensive understanding of pathological mechanism. Bone Res. 2017;5:16044. doi:10.1038/boneres.2016.44 Vennu V, Bindawas SM. Relationship between falls, knee osteoarthritis, and health-related quality of life: data from the Osteoarthritis Initiative study. Clin Interv Aging. 2014;9:793-800. doi:10.2147/CIA.S62207 Centers for Disease Control and Prevention. Important facts about falls. Additional Reading Arthritis National Research Foundation. Types of arthritis. By Carol Eustice Carol Eustice is a writer who covers arthritis and chronic illness. She is the author of "The Everything Health Guide to Arthritis." See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Cookies Settings Accept All Cookies