This conversation-analytic study investigates anamnestic interviews with patients of an Austrian headache outpatient ward. Via a detailled analysis of transcipts and freeze frames from the videos it will be reconstructed step by step how pain is communicated and differentiated, which strategies patients and doctors use for this purpose and which problems and eventually difficult courses of interaction result from this.The analysis shows that patients on their own accord do not orient towards the medical categories. In the interviews, patients' subjective and life-world-based pain-differentiations have to be transformed into the professional medical diagnostic classifications. This proves to be a genuinely interactive task. As a result of the analyses, the concept of "Interaction based medicine" is suggested here - a concept which takes into account the joint interactive construction of illness meaning in the medical interviews and highlights the need for interaction-centered research into doctor-patient-communication.