Question
I am 26 years old, My occupation is to continuously work on computer (sitting)At times I have difficulty in standing & sitting upright. i.e. I have a tendency to slouch back while I am working on PC, Can it be because of slipped disk? I also want to know what are the symptoms of slipped disk & when is the right time to see a doctor?  Can exercise on treadmill or cycling help in this regard?

Answer
Your most likely cause of pain is not a slipped disc, but of a spasm of the Psoas and Iliacus muscles.  These are the "core" muscles that you hear about, and sitting tends to weaken them.  If you go to http://www.floota.com/PsoasStretch1.html you can see how to stretch it.  A disc would most likely give pain radiating from the spine to the buttocks or legs, as well as numbness.  As always, without an exam it would be difficult to asses the condition you have.