When should I be concerned about a swollen knee?

When you notice a swollen knee, watch out for warning signs that might mean something serious is happening. If the knee swelling comes with fever, chills, or makes the knee feel very hot and tender, it could be a sign of infection such as septic arthritis, which needs quick medical care. Also, if you experience intense pain, sudden swelling after an injury, or if the knee feels unstable and hard to move, these can be reasons to see a doctor quickly. In children, doctors pay extra attention to these signs to make sure they are not dealing with a joint infection. In adults, sometimes knee swelling is related to long-term conditions like osteoarthritis; however, even then, if the swelling suddenly gets worse or is accompanied by new pain or redness, it should be checked out. If you're experiencing any of these symptoms and want to better understand what might be causing them, try our free AI symptom checker to help guide your next steps. Remember, taking care of your knee early helps prevent further problems, so if you have any of these warning signs, it's a good idea to get help.