Knee pain can have different causes. Being overweight puts you at greater risk for knee problems. Overusing your knee can trigger knee problems that cause pain. If you have a history of arthritis, it could also cause knee pain.
Here are some common causes of knee pain:
- Arthritis -- Including rheumatoid arthritis, osteoarthritis, lupus, and gout
- Baker cyst -- A fluid-filled swelling behind the knee that may occur with swelling (inflammation) from other causes, such as arthritis.
- Cancers that either spread to your bones or begin in the bones
- Osgood-Schlatter disease
- Infection in the bones of the knee
- Infection in the knee joint
Injuries and Overuse
- Bursitis -- Inflammation from repeated pressure on the knee, such as kneeling for a long time, overuse, or injury
- Dislocation of the kneecap
- Fracture of the kneecap or other bones
- Iliotibial band syndrome -- Injury to the thick band that runs from your hip to the outside of your knee
- Patellofemoral syndrome -- Pain in the front of your knee around the kneecap
- Torn ligament. -- An anterior cruciate ligament (ACL) injury, or medial collateral ligament (MCL) injury may cause bleeding into your knee, swelling, or an unstable knee
- Torn cartilage (a meniscus tear) -- Pain felt on the inside or outside of the knee joint
- Strain or sprain -- Minor injuries to the ligaments caused by sudden or unnatural twisting
When to Contact a Medical Professional
Call your provider if:
- You cannot bear weight on your knee.
- You have severe pain, even when not bearing weight.
- Your knee buckles, clicks, or locks.
- Your knee is deformed or misshapen.
- You cannot flex your knee or have trouble straightening it all the way out.
- You have a fever, redness or warmth around the knee, or a lot of swelling.
- You have pain, swelling, numbness, tingling, or bluish discoloration in the calf below the sore knee.
- You still have pain after 3 days of home treatment.