Osteoarthritis is a degenerative joint disease characterized by the breakdown of cartilage, leading to pain, stiffness, and reduced mobility. It most commonly affects weight-bearing joints such as the knees, hips, and spine but can also impact the hands. This condition typically develops gradually and is often associated with aging, but can be influenced by other factors such as genetics, previous joint injuries, and obesity. Unlike inflammatory arthritis, osteoarthritis does not involve systemic inflammation and usually remains localized to the affected joints.

Several factors can increase the risk of developing osteoarthritis, including age, gender, obesity, and joint injuries. Individuals over the age of 50 are particularly susceptible, with women more likely than men to develop the disease post-menopause. Genetic predisposition may also play a role, as a family history of osteoarthritis can elevate one's risk. Additionally, occupational or recreational activities that place repetitive stress on joints can contribute to the early onset of the condition.

Common symptoms of osteoarthritis include joint pain and stiffness, particularly after periods of inactivity or overuse. Individuals may experience swelling, tenderness, and a reduced range of motion in the affected joints. As the condition progresses, they might also notice a grating sensation or sound (crepitus) during movement. Symptoms can fluctuate, with periods of exacerbation and relief, and may significantly impact daily activities and quality of life.

Osteoarthritis is primarily caused by the degeneration of joint cartilage and underlying bone, often as a result of aging, overuse, or injury. Risk factors include obesity, genetics, joint malalignment, and previous joint injuries. This condition occurs when the normal balance between the synthesis and degradation of cartilage is disrupted, leading to the breakdown of cartilage and changes in the surrounding bone, ligaments, and synovial fluid.

Diagnosis of osteoarthritis primarily involves a thorough medical history and physical examination, with a focus on joint symptoms and functional limitations. Imaging studies, such as X-rays or MRI, may be utilized to assess the extent of joint damage and to rule out other potential causes of joint pain. Joint fluid analysis is sometimes performed to exclude inflammatory arthritis. The diagnosis is typically made when characteristic clinical and radiological findings align with the patient's reported symptoms.

Treatment for osteoarthritis focuses on managing symptoms and improving joint function. Initial approaches may include lifestyle modifications such as weight management, physical therapy, and exercise, along with nonsteroidal anti-inflammatory drugs (NSAIDs) for pain relief. In more severe cases, corticosteroid injections, hyaluronic acid supplements, or even surgical interventions like arthroscopy or joint replacement may be necessary to restore mobility and alleviate pain.

While it may not be possible to prevent osteoarthritis entirely, certain lifestyle modifications can help reduce the risk or delay its onset. Maintaining a healthy weight through balanced nutrition and regular exercise can lessen stress on joints, particularly weight-bearing areas. Engaging in low-impact activities, strengthening exercises, and avoiding repetitive stress can also be beneficial. Early intervention and management of joint injuries may prevent further damage and limit the development of osteoarthritis in susceptible individuals.