I've Been Diagnose With Sciatica Few Months Ago I Had

I've been diagnose with sciatica few months ago I had two car accident in 12 months but after a recent accident the pain worsen but I'm a very active person I run half marathon and marathon my physiotherapy says I can continue running the more I ran the pain become better but only when I stand on sit the pain my question is how long will I have it and the dangers in the future I recently fall and the pain started from scratch