This article presents a biocultural approach to human health that integrates perspectives from anthropological political economy, ecology, and human adaptability. This approach frames local conditions in relation to macrohistorical forces, and focuses on the social relations that underlie health and responses to illness. It examines the coping responses of human agents operating with a "conditional rationality," and the multiple consequences to these responses. The approach is illustrated with results from a study on the relationship between health and household economy among small-scale farmers of the Nuñoa District in the southern Peruvian Andes. Poor health and nutritional status reflect historical and current economic conditions in the district. Households in illness plant half as many fields at twice the labor cost as healthy households. Among poor households the effects of illness on farming production are exacerbated by their inability to adequately supplement family labor with nonhousehold workers. The consequences of illness can force changes in access to resources and production strategies, thus shaping household health and economy in the future.