I have osteoarthritis in my left knee...i have been having terrible pain in my knee which radiates down the side of my leg for a week now..it even wakes me up at night...please help?

Orthopedic specialis: This is not characteristic of garden variety osteoarthritis to have such persistent pain even at rest. It could be a flare up but I recommend consulting an orthopedic specialist for diagnosis and treatment. I assume you've tried taking an anti-inflammatory medication like Advil or Aleve in the meantime. Try applying alternating cold and hot applications as well.