This paper will review theoretical approaches for research on mathematics-related affect from the 1990s until today. In order to organise this field, a metatheory of the affective domain is developed, based on distinctions along three dimensions: 1) cognitive, motivational and emotional aspects of affect; 2) rapidly changing affective states versus relatively stable affective traits; and 3) the social, psychological and physiological nature of affect. Using ideas from enactivism and other system theories, the third dimension is elaborated. The embodied perspective brings forth on the one hand the evolutionary basis of human affect, and on the other the individual developmental perspective. Classroom microculture and cross-cutting social variables (e.g., gender and ethnicity) are identified as two different ways of theorising the social dimension of mathematics-related affect.