Dear friend, we can take it step by step. If you don't remember any trauma or twisting your knee, that's okay. I would suggest that you first manage the pain, because there’s no reason to be in pain. You can apply ice to your knee for intervals of 15 to 30 minutes when it hurts and take Paracetamol (Acetaminophen) 500 to 1000 mg every 8 hours or Diclofenac (Voltaren) 50 to 75 mg every 12 hours for 3 to 5 days while you have pain. Then, for your knee, try not to run until it improves for a couple of weeks. It would be helpful to get a front and side X-ray to evaluate the bone and check for any fractures or anything. If that doesn’t provide any information, the knee and its ligamentous apparatus need to be properly assessed, and the best way to do that is with an MRI of the knee in T1, T2, and STIR sequences to consult with a specialist in traumatology and see what’s really going on or if it’s the menisci of the knee that are bothering you, particularly because those are meniscal symptoms, such as the sensation that the knee is locking or having pinching sensations near the kneecap. Finally, if all of that is normal, I would then start a rheumatological study, but a lot has to happen before that bridge because that’s the most unusual thing I can think of, and I don’t think it’s relevant right now. #DocChain