What could cause these bizarre symptoms?

What could be the cause of these symptoms, loss of the ability to walk?

• What could be the cause of these symptoms, awakening and not being able to walk on the right leg (some not all nights). Can't bend the left knee, cannot stand for prolonged periods of time. Cannot shop for more then an hour as my left foot/leg goes on me and I then have to use a walking stick. Some days I have to use it anyway. And a sharp pain from the ball of the left foot up through the leg as well as occasionally swollen ankles. Could it be Cancer?, I am booked for my doctor but I would like to have an idea to what can be the cause, an prepare for the best or worse. I understand diagnosis can't be made of the internet and thank you for your replies.

• Answer:

  Could be a majority of things. Slipped discs in the back,sciatic nerve being aggravated,edema(fluid retention),knee problems,neuropathy,arthritis,getting to more severe things could be MS, or MD. But the best thing to do is see your doctor as you have said