I have extreme pain in my knee accompanied by cracking and grinding under my kneecap when ever i move leg it feels as if my knee cap is shifting. what is this it pains more going down stairs then it does to climb them should i get this checked?

?Patello-femoral: syndrome? It occurs when the knee cap doesn't slide smoothly in the groove created by the femur & tibia. This causes irritation & inflammation. It's common in young women whose long bones may be growing faster than the stabilizing muscles. It's more notable going downstairs b/c of added stress of gravity and the greater range of motion of the knee cap. Yes, you should get this checked!!!!!

Yes: sounds like your problem is under kneecap. if it feels like it is shifting it may be unstable or maligned also. needs evaluation by ortho

Yes: This can be rubbing of the cartilage of the back of the kneecap - also called chondromalacia patella. This can occur with loose kneecaps also. You need to see your physician to get this evaluated. Knee exercies are important therapy.

Anterior knee pain: This is a common problem especially among young women. You should see an orthopedic surgeon or sports medicine doctor who will evaluate your knee and probably recommend physical therapy and perhaps a brace. If you are overweight, this will compound the problem as knee cap pressure is several times body weight descending stairs or squatting. Rarely, surgery will be required.