Stuttering from psychological trauma is called psychogenic stuttering, stuttering from physical injury is called neurogenic stuttering. The vast majority of people who stutter, though, have developmental stutters. Unless you can pinpoint a severe traumatic event in your life, or a serious injury after which you started stuttering, yours is developmental as well. Usually developmental stutters appear in people ages 2-5, though they can onset during puberty (more than likely your case), and there is such a thing as adult onset stutter. As for causes, for about half of stutterers with developmental stutters, it is genetic. For the other half, it seemingly comes out of nowhere. Research done so far has not concluded what precisely causes it. Even with the genetic component, the only evidence supporting it is that it's a trend for stuttering to run in families, and if a parent stutters their offspring is likely to stutter. What exactly is different in the DNA, and the specific affects this has on speech production is not known. Of course, there is even less known about developmental stutters whose stutters are not genetic. Unless you have had a serious injury involving nerve damage, after which you started stuttering, I would not see a doctor for that purpose. However, people with stutters are prone to self esteem issues, depression, anxiety, the like. Definitely talk to your doctor about treatment if it is applicable to you. Also, have you done speech therapy? Speech therapists teach you strategies and exercises to alleviate stuttering and increase fluency and confidence in speaking. Like all forms of therapy, you have to practice it every day for it to be effective. If you go to therapy for anxiety and just sit and talk for an hour, but do nothing the therapist tells you to do, it's not going to work, is it? Same thing applies here. See if your doctor can refer you to a speech therapist, you can also seek out a private practice if you wish. There's also the McGuire Programme many people here speak highly of, though I've never done it.