My Friend's Phobia

My friend has a social phobia. Every time when someone asks him about somithing he blush and answer somthing strange that nobody can understand. After that he runs away. I tried to talk to him but he didn't listen to me. He is a clever guy who can do every task in mathematics but he can't contact in a real life.  I think he need to go to doctor. Maybe he will give him a good advice.