The most basic requirement is that you have access to an experienced and skilled interpreter who can truly aid communication rather than getting in the way or distorting the messages that you and the patient want to communicate. (Incidentally, the term “interpret” generally refers to spoken language and “translate” to written language. The skills required for these two disciplines are obviously different, though many interpreters can translate as well.)

Being bilingual in English and another language does not qualify an individual as an interpreter (just as speaking English competently does not qualify an individual to teach the language). A professional interpreter has the special skills needed to fully understand what both people want to say and to make their messages clear in two languages. In addition, like any professional, a qualified interpreter knows her role, her limitations, and her responsibilities as an interpreter for others.

Qualified medical interpreters have additional skills that enable them to work effectively in health settings.
They have studied the basics of anatomy and physiology.
They may know the meanings of medical terms, diseases, and procedures in specialty areas and should be able to quickly make complex medical terminology understandable in the everyday language of the patients.
They know the words that may be “taboo” in the language or culture of the patient and the euphemisms that may be used instead.
They are familiar with the common health beliefs and practices of the cultures whose languages they speak. They understand and have been taught to handle the “triadic” relationship—the dynamics introduced by the introduction of a third person into a medical encounter.
They “must know how to engage both provider and patient effectively and efficiently in accessing the nuances and hidden socio-cultural assumptions embedded in each other’s language, which could lead to dangerous consequences if left unexplored.” (Massachusetts Medical Interpreters Association and Educational Development Center, Inc. 1995, 3)