Inflammation. Knee pain is a young patient is most commonly caused by inflammation from bursitis, tendonitis, or cartilage degeneration. A good physical exam and possible imaging could be used to confirm the diagnosis. Less common causes of knee pain are irritated nerve roots from the lumbar spine, infection, or tumors.
Yeah... I hear you..... But i need more detail to give you the right answer - how long you've had, what could have caused it, what other symptoms you might be having (swelling, redness, movement limitations, the exact pain location etc.).
Diagnosis. There are numerous reasons for knee pain and an evaluation is generally required. Most orthopedics exams are directed at identifying surgical problems. Patients are often surprised much of knee pain is poor control at the hip and ankle. Two YouTube videos review the concepts: https://www.youtube.com/watch?v=43Nh5aYwFnA https://www.youtube.com/watch?v=t6SXiDCMP3E.
Be seen. There are multiple potential causes of knee pain. A detailed exam and appropriate studies will likely show the specific diagnosis. Once the diagnosis is made, you can then discuss treatment options.