I was rear-ended on the highway and the other person took responsibility. The damage to my car was only $850.00. The injury I received was pulled

muscles and the joint that contects to the tailbone was injured. But I already had back issues including surgery and have been on meds that helped quite a bit. But, after this accident it flaried up my back issues. My doctor said I should tell the insurance company about this but I am not sure it that is the right thing to do. I am on Medicare and the insurance company has to tell them about my injuries and treatment. I am afraid that if I tell the insurance company that Medicare will not cover my back issues anymore and say the insurance has to, With only $850 damage they will not be inclined to pay me very much for pain and suffering. Also, I they are asking to settle (accident was early November 2012, How much should I ask for? Thank you so much for your time,