Pain in joints since last one year. Is?

Hello, This is regarding my friend who has been suffering from persistent pain in his ribs, knee, knuckles and all joints since last year. He had migraine issues too.He had fever also for too long, for months.He visited many doctors but everyone had different opinion. One of the doctor's even he said that he had typhoid and  he was on medication for a month for that.But when he did not feel better, he visited another doctor who said he did not have typhoid at any point.He is constantly under medication but it's doing no good. I also feel, he's stressed because of job issues and does not even interact with people as he used to do earlier.I am not sure if the pain he feels is actually there or it's just in his mind. It would be really great if you could suggest something. Thanks!