The knee is a complex joint made up of bones, cartilage, ligaments, tendons, and other soft tissues. Pain on its inner side can therefore have multiple causes.

1. MCL Injury

The medial collateral ligament stabilizes the inner knee. Sports injuries, falls, or sudden sideways forces can strain or tear it.

2. Medial Meniscus Injury

The medial meniscus is a cartilage structure that helps distribute forces through the knee. A tear may cause inner knee pain, swelling, catching, or stiffness.

3. Osteoarthritis

Age-related changes and previous injuries can contribute to osteoarthritis. Pain may become worse with walking, stairs, or prolonged standing.

4. Pes Anserine Bursitis

Small fluid-filled sacs called bursae reduce friction around the knee. Irritation of the pes anserine bursa can cause pain on the inner lower portion of the knee.

5. Tendon Problems

Tendons around the knee can become irritated through repetitive loading or sudden increases in activity.

6. Referred Pain

Sometimes discomfort felt around the knee can originate from another area, including the hip or lower back.

Because these conditions can produce overlapping symptoms, self-diagnosis is not always reliable. The duration of pain, injury history, swelling, range of motion, and physical examination can all help identify the cause.

If inner knee pain is persistent, recurrent, or interfering with normal activities, professional assessment can help determine the most appropriate treatment.