Knee keeps popping in and out, what causes this?

My knee keeps popping in and out,and this morning while I was working
I lost feeling in my leg,I can walk on it but all day I've done nothing but fall because my knee keeps going.what causes it and how can I stop

I would see a doctor if it is seriously giving you problems

OMG!! I've just learned about this in exercise science today!! do you do any sports or activities that stresses you knee a lot? you may have a musscle or joint dislocation!! - I just hope that you haven't torn a ligament!! seek medical help asap! and get it checked out and treated FAST!

I hope that it's nothing serious and that your doctor will be able to treat it well! (:

Go see an Orthopedist, that is a doctor who cares for the skeletal parts of your body. Preferably one who specializes in knees and other joints.