Below are some other common conditions that result in knee pain and their specific symptoms.
Injury. Strains and sprains to the muscles or ligaments in the knee can result in pain, swelling of the knee, and difficulty walking on the affected knee. An injury to the meniscus, which acts as the cushion in the knee, may also result in immediate pain and swelling around the knee.
Arthritis. Arthritis, both osteoarthritis and rheumatoid arthritis, usually comes on gradually. Therefore, knee pain, stiffness, and discomfort may build over time rather than immediately like knee pain from an injury might. Pain and stiffness are the most common symptoms of arthritis and pain usually increases when you move the knee and improves after you rest it. It may also feel worse at the end of the day.
Tendonitis. Patellar tendonitis, or jumper’s knee, usually causes people to feel pain and tenderness along with swelling around the knee. In addition, the area behind the lower part of the kneecap may also feel tender. Walking, running, and jumping may also make the pain worse.
Infection. An infection of the knee is a serious problem and should be treated by medical professionals immediately. Symptoms of infection include fever, nausea, chills, severe knee pain, knee stiffness, redness, swelling, and irritation.