This special issue explores the evolving landscape of medical semiotics of conventional biomedicine. With expansion we refer to the range of phenomena considered signs or symptoms of underlying disease, but also the growing anthropological attention to the medical sign system in ways which reach beyond classic semiotic analysis. The articles testify to the expansion in terms of empirical foci and theoretical contributions. As part of the introduction, we discuss three modes of reading symptoms within medical anthropology: the hermeneutic, material, and critical readings, all highlighting the crucial role of medical anthropology in understanding the biosocial and cultural dimensions of medical semiotics.