Like all other witnesses, a medical expert witness is usually called to testify in civil and criminal cases; also they may be hired to state their professional opinions at mediation or negotiation proceedings. These types of witnesses are called experts due to their professional knowledge about a particular field in medical cases. This person should have the expertise in medical health care profession beyond of an average person. Medical expert witnesses vary in different fields to which that person possesses the specialized knowledge. This type of experts educates the court and the jury about a specific field which is the subject under consideration in a proceeding. Normally an attorney can establish the credentials of the medical expert witness before he can render an opinion by asking him questions regarding his educational background, training experiences and skills in his field of expertise. Only then will the judge qualify that person as a medical expert witness.
Unlike a regular court witness who is not allowed to state personal opinions regarding the subject at hand, an expert witness is required to state the facts within their profession and specialized field. For medical instances, if a person has broken his leg, the witness should not only testify that the leg is broken, instead he will specify and educate the court on how the leg is broken for medical statements such as the severity of the brake or the amount of medical procedures like physical therapy for the recovery. Most often than not, a medical expert witness is being paid for the services he rendered in a court proceeding.