I am 63 year old. In general I have good physique and the entire day busy in some or other activities. For the last few months I am feeling 'numbness' on my left thigh (outer area) if stand for more than 15-20 minutes. After sitting few mints it will be ok. I observed it when I was in kitchen to do some cooking. Please advice me about the seriousness of the problem and how I can cure it?