Evaluated for sciatica: in servere pain for longer than 2wks already. how long until it gets better?

Depends: Most causes of low back pain will resolve with conservative treatments (heating pads, anti-inflammatories, rest etc.) within 6 weeks. If it doesn't it should be evaluated further. Also, if you are having radiation of pain into the legs, leg weakness, difficulty urinating or numbness in the groin area, you should be evaluated now.

Several weeks: Each person needs to be evaluated on an individual basis. There can be several reasons for your pain. While it can certainly resolve on its own in several weeks, why wait. I treat aggressively to decrease inflammation, reduce pain, improve function and quality of life. A thorough physical exam and diagnostic studies will help determine what treatment will be best depending on your diagnosis.

4-6 weeks: Initially the symptoms last 4-6 weeks and if your body heals like it supposed to then pain relief starts. However disc herniations which are the cause of majority of sciatica symptoms last for 6-9 months and therefore people can have pain during that time as well. If not better after 6 weeks see a spine specialist to evaluate this further.