<s>[INST] I have a bump under my (L) knee on the front right of my tibia, It does not hurt to walk or move my knee but I do notice pain when I bend, add excess weight or when I run what could this be? I lift weights 5 days a weeek and am verry active? I have not done any cardio or leg training for the past three weeks since I have noticed this. [/INST] Welcome to ChatDoctorI require more detailed description of bump to come to a diagnosis and also your age. Since you are active and doing weight lifting this may be joint effusion due to arthritis. Orthopedic surgeon opinion must be taken for this and if required, knee x-ray. Rest to the knee and anti-inflammatory like Coquitlam tablet will improve the swelling if it is due to arthritis, but you should see orthopedic surgeon before starting any treatment. Regards. </s>