All teachers have an obligation to include all students in teaching, by amongst other things, taking everyone’s individual conditions and needs into account. There are a number of different reasons why students do not want to participate in the teaching of sports and health, one of these may be discomfort during menstruation. The aim of this investigation is to develop insights into how physical education teachers at junior high school and high school handle situations that may arise in teaching linked to menstruation. To achieve this aim, a qualitative study has been carried out with semi-structured interviews, in which eight teachers from different junior high and high schools participated. The results show that the teachers' knowledge of menstruation is individual and that the problems look different for every student. The teachers agree that students who come to physical education lesson with menstrual problems are expected to participate and do the best they can based on the conditions they have for that day. The teachers believe that they can adapt their teaching and they would rather see the students participate at a lower level than not at all. In the discussion, the importance of challenging or resisting the stigma around menstruation is stressed. The stigmatization is what causes partly a dark talk, because the girls choose to hide their periods from others, and partly the reluctance to discuss menstruation. By talking more openly about menstruation, the subject can be normalized, and the stigma broken.