How To Cure Constant Numbness And Tingling Sensation In The Lower Area Of Right Thigh?

I have been experiencing a constant numbness/tingling sensation in the lower area of my right thigh, just above the knee. At first I thought it was from sleeping on my right side for too long each night, but the numbness doesn t go away during the day. The sensation has been present for at least a year now. Sometimes, I will feel a painful twinge in the area, but other than that, I haven t been experiencing any pain....What should I do? Thanks!