There are a couple of possible causes of medial knee pain. The first and most common is an injury. This can happen when you strain yourself during a high-impact sport like running. Anything that puts a strain on the knee joint is a possible cause for strain.
Another cause of medial knee pain is bursitis. This condition occurs due to inflammation in a tissue called the bursa. These are small fluid-filled sacs that stop muscles, tendons, and bones from rubbing together. Inflammation of the pes anserine bursa may lead to inner knee pain. This can be caused by an acute injury or overuse of the knee joint.
A sprain or tear may also cause medial knee pain. Inner knee pain can be caused by a sprain or tear in the medial collateral ligament. This type of injury almost results in immediate pain and swelling. You may also have medial pain when running due to a torn meniscus, which is the cartilage that lines the knee joint. The meniscus sometimes wears down over time.
This condition can also be caused by knee osteoarthritis, a degenerative condition that causes a person’s cartilage to wear down. Your knees are very vulnerable to this.
Another condition that may give rise to medial knee pain is medial plica syndrome, which causes inflammation of the plica that may be in the knee. This overuse injury occurs most commonly after a person has increased their activity level. Medial knee pain can also be caused by rheumatoid arthritis, an autoimmune disease that causes inflammation in the body.