About 528 million people worldwide were living with osteoarthritis as of 2019, according to the World Health Organization. That number represents a 113% increase from 1990, and projections suggest it will keep climbing. Osteoarthritis is the most common form of arthritis and one of the leading causes of disability globally, ranking as the seventh leading cause of years lived with disability among adults 70 and older.
Global Numbers at a Glance
The 528 million figure captures all joints combined, but the knee accounts for the largest share by far. Roughly 365 million people have osteoarthritis in the knee, making it the single most affected joint. The hip and hand are the next most common sites. Many people have osteoarthritis in more than one joint, so the total across individual joints exceeds the overall count of people affected.
These numbers are almost certainly undercounts. Osteoarthritis is diagnosed through a combination of imaging and clinical symptoms, and millions of people in lower-income countries never receive a formal diagnosis. The true global burden is likely higher than what studies capture.
Prevalence in the United States
In the U.S., about 18.9% of adults 18 and older reported a diagnosed form of arthritis in 2022, based on CDC survey data. That figure includes osteoarthritis along with other types like rheumatoid arthritis and gout, but osteoarthritis is the most common form by a wide margin. Previous CDC estimates have placed the number of Americans with osteoarthritis specifically at over 32 million.
The financial burden is substantial. People with osteoarthritis in the U.S. incur average annual medical costs of about $8,644, compared to $2,273 for similar adults without the condition. Pharmacy costs alone run roughly $2,179 per year. For those who eventually need joint replacement surgery, a single knee replacement averages around $17,400, while a hip replacement averages about $18,400.
Who Gets Osteoarthritis Most Often
Age is the strongest predictor. About 73% of people living with osteoarthritis are older than 55. The condition develops as cartilage gradually breaks down over decades of use, and cumulative wear becomes harder for the body to repair with age. That said, osteoarthritis is not exclusively a disease of older adults. Joint injuries, obesity, and physically demanding occupations can accelerate the process, and younger adults do develop it, particularly in joints they’ve previously injured.
Women are disproportionately affected, making up 60% of all osteoarthritis cases worldwide. The gap widens after menopause, suggesting that hormonal changes play a role in cartilage health. Women also tend to develop more severe osteoarthritis in the knee and hand compared to men of the same age.
Why the Numbers Keep Rising
Two forces are driving the increase. First, the global population is aging. As more people live into their 70s and 80s, the pool of people old enough to develop osteoarthritis grows. Second, obesity rates have risen sharply worldwide. Excess body weight places additional mechanical stress on weight-bearing joints, particularly the knees, and also promotes low-grade inflammation that accelerates cartilage breakdown.
Projections from the Global Burden of Disease Study estimate that by 2050, knee osteoarthritis cases will increase by about 75% compared to 2020 levels. Hip osteoarthritis is projected to rise nearly 79%, and other joint types by as much as 95%. Hand osteoarthritis is expected to grow by roughly 49%. These are not small upticks. They represent hundreds of millions of additional cases within a single generation.
The Disability Burden
Osteoarthritis rarely appears on lists of life-threatening conditions, but its impact on quality of life is enormous. The global rate of years lived with disability from osteoarthritis was 255 per 100,000 people in 2020, a 9.5% increase from 1990. That measure captures the years people spend with reduced mobility, chronic pain, and limited ability to work or perform daily tasks.
For many people, osteoarthritis means difficulty with stairs, trouble gripping objects, or pain that disrupts sleep. It contributes to physical inactivity, which in turn raises the risk of heart disease, diabetes, and depression. The condition’s ripple effects extend well beyond the joints themselves, making it one of the most underappreciated public health challenges worldwide.
Which Joints Are Most Affected
The knee dominates. With 365 million cases globally, it accounts for more osteoarthritis than any other joint. This makes sense given the mechanical load the knee absorbs during walking, climbing, and standing. The knee joint bears forces of two to three times your body weight with every step, and up to five times during activities like squatting or descending stairs.
Hip osteoarthritis is the second most common and tends to cause deep, aching pain in the groin or outer thigh that worsens with activity. Hand osteoarthritis, the third most common, often affects the base of the thumb and the finger joints closest to the nails. It can make fine motor tasks like buttoning a shirt or opening a jar increasingly difficult. Spine osteoarthritis is also widespread but is tracked less consistently in global data because it overlaps with other causes of back and neck pain.