<s>[INST] Hey doc! my name is nicole and i am 19 years old . i have this terrible knee pain. it feels very tired everytime i wal or sit and it annoys me .sometimes the whole leg feels heavy or tired . i  m afraid to go to the doc cuz i m too young to do a surgery . pleaaase tell me what it could  be [/INST] Hi, In my opinion you shouldn't worry from your given history you are still young for operative treatments, and you may not need it now at all unless you had a past severe injury causing it to swell and sore. It could be osteoarthritis, gout, rheumatoid arthritis or a minor trauma that you didn't recognize. For now, I suggest hot massages with topical gels, painkillers like ibuprofen 500 mg tabs when needed, avoid vigorous movements and standing for a long time, wear knee supports, avoid bending it and elevate it will be effective. If pain persists visit your physician for proper evaluation. Please consider a 5-star rating with some positive feedback if the information was helpful. Hope the above information helps you. Any further clarifications feel free to ask. </s>