Does a psychologist treat functional disorders?

Yes: Psychologist do treat functional disorders as there are might be difficulties coping with illness and understanding from families. There are psychologists who are specializing in health psychology -- effects of medical conditions on a person and person's relationship with the people and the world as well as how to cope with physical illness effectively.

Yes.: By their nature, functional disorders are those that involve a physiological impairment but yet have no known medical/physiological basis. Those disorders that arr truly psychological can be treated through therapeutic interventions. However, those that are later determined to have an organic cause need to also be treated by a medical professional.