What Causes Leg Pains, Fever With Vomit Like Feelings?

This is Ayub from India. My wife's age is 33 yrs. She is been having pain in her legs combined with Vomit like feeling and fever for 2 days. I took her to a local doctor & he advised some pills which relived her for some time but now problem has started again. This is the first time she is facing this problem.