ASL interpreting

American Sign Language (ASL) is a language that uses hand signs, facial expressions, and body postures to communicate ideas. ASL is a rich, complex language on par with spoken languages, and employs rules of phonology, syntax, morphology, etc. using manual/visual modes of communication, where spoken languages rely on the oral/aural modes of communication. ASL is used by Deaf and hard-of-hearing people in the North American continent, often as their primary language.
Language interpretation is defined by the International Standards Organization (ISO) as the following: "Rendering a spoken or signed message into another spoken or signed language, preserving the register and meaning of the source language content." ASL interpreters must understand the subject matter at hand, be able to reliably and fluently transmit the information without bias, and be accustomed to navigating any kind of social situation. ASL interpreting is a multifaceted job, requiring management of linguistic, interpersonal, and environmental issues.
Training for ASL interpreters is highly varied, as are the education and certifications required for employment. Career and medical support for ASL interpreters has become a topic of concern and study in the last several years, in response to a high rate of interpreter burnout that has led to a shortage of ASL interpreters across the United States.
The role of ASL interpreters.
ASL interpreters work in a large variety of environments, including medical, legal, educational, mental health, vocational, and other environments. Interpreting is often viewed as a practice profession (other examples include law, teaching, counseling, medicine, etc.), which requires careful judgement of interpersonal and environmental factors as well as expertise in the skills of the profession itself. The interpreter must be able to understand the concepts they are seeing and hearing, perform the mental translation, and communicate them effectively in the second language. Although the interpreter usually intends to be in the background of the conversation and not contribute beyond interpretation, overcoming differences between the languages often requires them to make judgements which might alter the flow of communication. As with any two languages, ASL and English do not have a one-to-one word correspondence, meaning interpreters cannot simply translate word-for-word. They must determine how to effectively communicate what one interlocutor means, rather than strictly what they say, to the other. Sometimes these judgement calls and various linguistic barriers cause the interpreters to affect the flow of conversation. For example: if a medical professional asks a patient if they are "sexually active," the interpretation can become complicated, because while the English phrase makes no overt reference to a partner or a specific act, in ASL it is very difficult to discuss sexual activity without reference to a partner or act. Consequently, the interpretation from English to ASL may result in the patient responding in dialogue rather than with the "yes/no" answer that the doctor might be expecting.
Often, interpreters must manage situations in which the interlocuters' comments include connotations that may be lost on the other party, and the interpreter is left with the decision of how to convey those connotations, or whether they even have the authority to do so. For example, a doctor may ask an interpreter to relay to the patient, "There is nothing more we can do for you. We're going to make you as comfortable as we can." While the literal meaning of the expression is easily conveyed, the interpreter would be aware that the euphemistic nature of this phrase in English might be lost on the deaf patient. Thus, the interpreter would put in the position of bluntly telling the patient that they are going to die. In a situation such as this, the interpreter may elect to discuss the interpretive difficulty with the doctor and allow the doctor the opportunity to communicate with the patient more directly and less euphemistically. The interpreter must not only be able to recognize the linguistic barrier in this situation, but also must be aware of the interpersonal factors involved in the situation and the limitations of their role.
Challenges for the ASL interpreter.
Degree programs in ASL Interpreting are available at colleges, universities, and technical schools across the country, ranging from associate degrees to master's degrees. In addition, interpreters work with mentors, attend workshops, and get certifications to become more adept, gain experience, and open additional career opportunities. 
Other interpreters are children of Deaf adults (CODAs) and are typically exposed to ASL and Deaf culture at a young age, giving them an advantage over later learners. In recent years, much research has gone into discerning whether ASL interpreters have access to adequate, specialized, real-world training and career support systems to ensure success and protect against interpreter burnout. Many studies note interpreter reports of frustration with training that proved inadequate to deal with real-world problems, and a lack of professional support.
A variety of factors contribute to stress for the interpreter: variable working conditions, expectations, and even understanding of the interpreter's role and responsibilities can all play a part. Often, interpreters are party to emotional or traumatizing experiences because they are needed to interpret in those situations, with no outlet for dealing with their internal reactions to them. Interpreters also experience physical stress, often in the form of cumulative trauma disorders such as carpal tunnel syndrome that may require them to take time off work to recuperate.
Interpreting ASL as a profession carries a variety of demands. Robyn Dean and Robert Pollard, in applying control-demand theory to the profession, identify four categories of demands:
The relative lack of interpreter post-graduate training does little to prepare interpreters to deal with the varied demands above, which each may be prominent depending each particular interpreting assignment. Heller et al. (1986), Swartz (1999), and Watson (1987) (cited in Dean and Pollard 2001) all agree that this environment is a large contributor to interpreter burnout and, by extension, the current shortage of ASL interpreters in the United States. However, steps are being taken by several entities, including the Conference of Interpreter Trainers (CIT) and the Registry of Interpreters for the Deaf (RID), to create and adopt standards by which training programs can be judged. Laurie Swabey and Karen Malcolm's book "In Our Hands: Educating Healthcare Interpreters" (2012) discusses the specific difficulties that interpreters face in medical fields. The book covers issues that arise in mental health interpreting, the risks of vicarious trauma, explorations of authentic interactions to aid in discourse training, etc. "Topics in Signed Language Interpreting: Theory and Practice", edited by Terry Janzen (2005), covers, among other things, the issues that arise with simultaneous interpretation, ethics and professionalism as they relate to interpreting, and a Deaf community perspective on best practices for interpreters. Still, a cohesive standard for postgraduate training and career support for ASL interpreters has yet to materialize.