2 weeks ago the left side of my left leg began hurting very bad, it feels numb and heavy. it often gets weak when i stand and go up or down steps. It hurts to sit for any amount of time, walking does help and it doesn't hurt but is always numb.. from my upper hip all the way down my leg but not to my foot and my knee feels tight and heavy. I thought it started with a bout of sciatica.. is this possible?