Arthritis is one of the most common chronic conditions in the world. In the United States alone, an estimated 78.4 million adults are projected to have doctor-diagnosed arthritis by 2040, representing about one in four adults. Globally, osteoarthritis alone affected 595 million people in 2020, or roughly 7.6% of the world’s population. Whether you’re wondering about your own risk or trying to understand a diagnosis, the numbers make one thing clear: arthritis is extremely common.
How Many People Have Arthritis in the U.S.
Arthritis isn’t a single disease. It’s an umbrella term covering more than 100 conditions that cause joint pain, swelling, and stiffness. The most prevalent form, osteoarthritis, results from gradual wear on joint cartilage. Rheumatoid arthritis, gout, psoriatic arthritis, and lupus-related arthritis are among the other major types. When public health agencies report arthritis numbers, they’re typically counting all of these together.
CDC projections estimate that 78.4 million U.S. adults will have doctor-diagnosed arthritis by 2040, a 49% increase from 2015 levels. That jump is driven largely by an aging population, since the risk of arthritis climbs sharply with age, and by rising rates of obesity, which puts extra stress on weight-bearing joints.
The condition also affects children. An estimated 220,000 U.S. children and adolescents under 18 have been diagnosed with some form of arthritis, a rate of about 305 per 100,000.
Risk by Age and Sex
Age is the single biggest predictor. Among adults aged 18 to 44, only about 6% have arthritis. That number roughly quadruples by middle age: 22.3% of men and 29.3% of women aged 45 to 64 are affected. By age 75 and older, 44.7% of men and 57.8% of women have the condition. In other words, more than half of older women live with some form of arthritis.
Women are affected more often than men across every age group. The gap is especially pronounced for rheumatoid arthritis, where women are two to three times more likely to be diagnosed. Hormonal differences, immune system variations, and joint anatomy all play a role in that disparity.
Osteoarthritis: The Most Common Type
Osteoarthritis accounts for the largest share of arthritis cases worldwide. A 2023 analysis published in The Lancet Rheumatology found that 595 million people had osteoarthritis in 2020, making it the most prevalent joint disease on the planet. The knee is the most commonly affected site, followed by the hip and hand.
Those numbers are expected to grow dramatically. Compared with 2020 levels, knee osteoarthritis cases are projected to increase by about 75% by 2050, and hip osteoarthritis by roughly 79%. Population aging explains part of this, but rising rates of obesity and joint injuries from sports and physical labor are also contributing factors.
Rheumatoid Arthritis, Gout, and Psoriatic Arthritis
Rheumatoid arthritis is an autoimmune condition where the immune system attacks the lining of the joints, causing chronic inflammation. The World Health Organization estimates that 18 million people worldwide were living with rheumatoid arthritis in 2019. It tends to appear between ages 30 and 60 and can affect joints on both sides of the body symmetrically, which distinguishes it from osteoarthritis.
Gout, caused by a buildup of uric acid crystals in the joints, affected about 9.2 million U.S. adults in 2015 to 2016, a prevalence of 3.9%. While the overall rate has remained relatively stable over the past decade, the total number of people affected has grown simply because the population has grown. Gout is more common in men and often strikes the big toe first.
Psoriatic arthritis develops in some people who have the skin condition psoriasis. Its prevalence in the general population is about 112 per 100,000 adults, making it less common than osteoarthritis or gout. Among people who already have psoriasis, however, the risk is much higher: roughly 17% to 22% go on to develop joint involvement.
How Arthritis Limits Daily Life
The real-world impact of arthritis goes well beyond joint pain. In 2023, an estimated 24.8 million U.S. adults with arthritis reported that the condition limited their daily activities, nearly 47% of all adults with the diagnosis. That includes difficulty with basics like walking, climbing stairs, gripping objects, or getting dressed.
Women with arthritis are more likely to report these limitations (52%) than men (42%). Income matters too: about 64% of adults with arthritis living near or below the poverty line reported activity limitations, compared with 41% of higher-income adults. That gap likely reflects differences in access to treatment, the physical demands of certain jobs, and the ability to modify work or living environments.
People with arthritis who also have other chronic conditions face an even steeper burden. Among those with heart disease, 73% reported activity limitations. For those with chronic lung disease, the figure was 75%. Arthritis rarely exists in isolation, and when it overlaps with other health problems, the combined effect on mobility and independence compounds quickly.
The Economic Toll
Arthritis carries substantial costs at both the personal and national level. Total U.S. costs attributed to arthritis and related conditions reached approximately $128 billion in 2003, the most recent year with comprehensive national estimates. That figure includes $80.8 billion in direct medical costs (doctor visits, medications, surgeries, physical therapy) and $47 billion in indirect costs from lost wages and reduced productivity. Adjusted for medical inflation, today’s total is considerably higher.
For individuals, the financial strain shows up in prescription costs, copays for physical therapy, and, for many, reduced earning capacity. About 76% of adults with arthritis who also reported a disability said arthritis limited their activities, and those who are unable to work cite joint disease as a primary reason.