Arthritis in the hands has several distinct causes, ranging from cartilage breakdown and autoimmune attacks to crystal deposits and past injuries. The most common type, osteoarthritis, affects roughly 27% of adults over 45 and is driven by a combination of genetics, repetitive use, inflammation, and metabolic factors. But osteoarthritis isn’t the only culprit. Rheumatoid arthritis, psoriatic arthritis, gout, and previous hand injuries can all damage hand joints through very different mechanisms.
Osteoarthritis: More Than Simple Wear and Tear
Osteoarthritis is the most frequent cause of hand arthritis, and it’s widely misunderstood as just “wearing out” the cartilage. The reality is more complex. Yes, cartilage gradually deteriorates, but the process is actively driven by inflammation inside the joint. Inflammatory signaling molecules ramp up the production of enzymes that break down the structural proteins holding cartilage together. This creates a self-reinforcing cycle: damaged cartilage triggers more inflammation, which accelerates further damage.
The joints most commonly affected are the fingertips (where Heberden’s nodes form), the middle finger joints, and the base of the thumb. Over time, the body responds to cartilage loss by growing small bone spurs around the joint edges, which contribute to the knobby appearance many people associate with hand arthritis.
Genetics Play a Major Role
Heritability of hand osteoarthritis is estimated at 48 to 65%, making genetics one of the strongest risk factors. If your parents or grandparents had bony nodules on their finger joints, your chances are significantly higher. Heberden’s nodes specifically follow a pattern of inheritance: they’re passed as a dominant trait in women (meaning you only need the gene from one parent) and a recessive trait in men (requiring the gene from both parents). This partly explains why hand osteoarthritis is more common in women.
Researchers have identified several chromosomal regions linked to hand osteoarthritis, along with candidate genes involved in cartilage structure and mineral regulation. One example: variations in a gene that helps prevent abnormal calcium buildup in cartilage have been linked to higher risk. People carrying that risk variant produce less of the protective protein, potentially allowing cartilage to calcify and stiffen prematurely.
How Obesity Affects Non-Weight-Bearing Joints
It makes intuitive sense that excess weight damages knees and hips, but hands don’t bear body weight. So why is hand osteoarthritis more common in people with obesity? The answer lies in fat tissue itself. Adipose tissue isn’t just passive storage. It actively produces inflammatory signaling molecules called adipokines, which enter the bloodstream and reach joints throughout the body, including the fingers.
These adipokines trigger the same destructive cascade seen in weight-bearing joints. They increase levels of inflammatory compounds in joint fluid, activate cartilage-degrading enzymes, and can infiltrate cartilage directly. This chronic, low-grade systemic inflammation helps explain why maintaining a healthy weight protects joints you’d never think of as being affected by your waistline.
Repetitive Hand Use and Occupational Risk
Certain types of hand work significantly increase your risk, particularly for arthritis at the base of the thumb. A large study of construction workers found that high grip force, frequent pinch gripping, repetitive wrist bending, regular use of handheld tools, heavy lifting, and exposure to hand-arm vibration all raised the risk by 30 to 54%. The relationship followed a dose-response pattern, meaning more exposure meant higher risk.
Workers most affected included sheet-metal workers, glassworkers, and woodworkers, all occupations requiring strong gripping, repetitive wrist motion, or prolonged tool use. But you don’t need to work in construction. Any activity involving sustained pinch grip or repetitive hand motions over years can contribute, from hairdressing to assembly-line work to prolonged manual crafting.
Rheumatoid Arthritis: The Immune System Attacks the Joint Lining
Rheumatoid arthritis has a completely different cause. It’s an autoimmune disease in which the immune system mistakenly attacks the synovium, the thin membrane lining the inside of joints. The small joints of the hands and wrists are typically among the first affected, often symmetrically (both hands at once).
The process begins before you ever feel symptoms. Autoantibodies circulate in the blood years before joint inflammation becomes noticeable. At some point, a breakdown in immune tolerance allows these antibodies to form complexes that enter the synovium. Once there, components of both the innate and adaptive immune systems amplify the response, recruiting inflammatory cells, thickening the joint lining, and eventually eroding the cartilage and bone underneath.
Why the hands specifically? Blood vessels in the fingers and other extremities appear to have unique properties that make them more permeable to these immune complexes. This increased permeability allows inflammatory cells to flood into the joint tissue more easily in the hands and feet than in larger, more central joints. The result is the characteristic swelling, warmth, and stiffness in the knuckles and wrists that often marks early rheumatoid arthritis.
Psoriatic Arthritis and “Sausage Fingers”
Psoriatic arthritis affects some people with psoriasis and has a distinctive pattern in the hands. Rather than targeting the joint lining like rheumatoid arthritis, it starts at the entheses, the points where tendons and ligaments attach to bone. These attachment sites are under constant mechanical stress, and in genetically predisposed individuals, that stress triggers an inflammatory response that spreads into surrounding joint tissue.
One hallmark is dactylitis, commonly called “sausage digit.” An entire finger swells uniformly rather than just at the joint, because the inflammation involves the tendon sheath and surrounding soft tissue along the full length of the digit. The swelling becomes so diffuse that individual joint outlines disappear.
Psoriatic arthritis also has a strong connection to the fingernails. The extensor tendon that attaches to the last finger bone extends into the nail root, making the nail essentially part of the enthesis. This is why roughly 80% of people with psoriatic arthritis have nail changes like pitting, ridging, or separation from the nail bed, and why the fingertip joints are so commonly involved.
Crystal Deposits in the Joints
Two types of crystal arthritis can affect the hands. Gout occurs when uric acid levels in the blood rise high enough for crystals to form inside joints. While gout most famously strikes the big toe, it can affect finger joints as well, especially in people who’ve had the condition for years. The crystals provoke an intense inflammatory reaction, causing sudden, severe pain and swelling.
Calcium pyrophosphate deposition disease (often called pseudogout) is another crystal-related cause. Calcium-containing crystals accumulate in joint cartilage and soft tissue, triggering inflammation and damage. In its chronic form, this condition commonly affects the knuckle joints and wrists and can mimic rheumatoid arthritis, with symmetrical swelling, stiffness, and even deformities of the hands and wrists. About 25% of people with this condition develop the chronic form. Certain metabolic conditions, particularly hereditary hemochromatosis (iron overload), increase the risk because excess iron interferes with the enzymes that normally clear pyrophosphate from joints.
Previous Hand Injuries
A broken finger, dislocated joint, or torn ligament can set the stage for arthritis years or even decades later. Post-traumatic arthritis develops through two simultaneous pathways. First, the initial impact kills cartilage cells, reducing the joint’s ability to maintain and repair its own cushioning surface. Second, the injury triggers an inflammatory response inside the joint that, if severe enough, causes ongoing cartilage degradation well after the fracture has healed.
The severity of the original injury matters. Higher-energy impacts produce more widespread inflammation in the joint lining within the first week, and that early inflammation predicts more significant cartilage breakdown down the line. In animal studies, degenerative changes became visible by eight weeks after injury. In humans, the timeline is longer but the pattern is the same: a single significant hand injury can lead to arthritis in that joint over the following years, particularly if the fracture involved the joint surface rather than the mid-shaft of the bone.
Hormones and Age
Hand osteoarthritis is notably more common in women, especially after menopause. Estrogen appears to have a protective effect on cartilage, and its decline during menopause coincides with a sharp rise in hand arthritis incidence. This hormonal shift, combined with the genetic inheritance patterns that favor expression of hand arthritis in women, helps explain why postmenopausal women are the group most frequently affected.
Age itself is a risk factor for every type of hand arthritis. Cartilage loses its ability to repair itself over time, the inflammatory environment in joints shifts toward more destructive signaling, and cumulative mechanical stress adds up. But age alone doesn’t cause arthritis. It creates the conditions where the other factors listed here, genetics, metabolic health, immune dysfunction, occupational stress, and old injuries, are most likely to tip the balance toward joint damage.