Knee pain is a common complaint that can be caused by a variety of factors, including injury, age-related wear and tear, overuse or underlying medical conditions. It often affects people who are involved in activities that require repetitive knee motions such as running, jumping or climbing stairs. Knee pain can range from mild discomfort to severe agony, depending on the cause and severity of the condition. Some common symptoms associated with knee pain include swelling, stiffness and tenderness around the joint. In some cases, knee pain may be accompanied by clicking or popping noises when the joint is moved. There are many potential causes for knee pain; if it persists it is important to see a doctor to get an accurate diagnosis and treatment plan. Arthritis is one of the most common causes of chronic knee pain in adults; there are many different types of arthritis with different treatments available. Other causes of knee pain can include tendonitis (inflammation of tendons), bursitis (inflammation of bursae) and patellar tendinopathy (overuse injury). Injury-related causes may include fractures, sprains or meniscus tears. Knee injuries should always be checked out by a physician if there is any substantial degree of discomfort or swelling present. Treatment for knee pain depends on its underlying cause but can include physical therapy, anti-inflammatory medications, corticosteroid injections and even surgery in more severe cases.