Do quardricep exercise

If it's too frequent then it can be joint laxity..

Crepitus in the knee is common and usually painless. There’s no need to be concerned about it. However, if you have pain associated with the crackling and popping sounds, this could indicate a problem osteoarthritis.

Yes,it could be muscle weakness,laxity is becoming less .but exact treated is given when proper diagnosis and assessment is done . consultation is required immediately Do isometric of knee exercise Theraband exercise 5-10 min brisk walk Ice pack 5-10 min

It would be great to know at what degree of knee bending you hear your knee click Why does that matter ? It helps me in advising you what degree of knee flexion or extension you can avoid so you won't provoke the knee Also , what kind of a runner are you? Marathon, Sprinter ? Helps me to understand the cause of the problem. Now , why is there a clicking sound ? Could be ligament laxity , muscle weakness etc

As per your complaint and age it's not an issue , being a runner must do proper warm up before u do any activity and followed by  cool down phase after you finish your activities. Better you wear normal knee supports during activities to maintain proper alignment of your knees; due to uneven surfaces or bad roads may hinder your activity.

This is common clicking sound, there is no need to worry you have symptoms like swelling pain or stiffness. do not overuse muscles, take healthy calcium rich diet. Do warmup properly before starting of running.

Consult Physiotherapist. Your pain and sound both will be vanished in like week once you start exercise. If you want to do it by yourself at home just consult us. We will provide you online guidence