This chapter examines how culture influences the content and application of medical knowledge. The current state of knowledge about pathology and treatment is not simply the outcome of a neutral process of scientific investigation and discovery, but is shaped by changing conceptual frameworks affected by more general cultural perspectives. The disease classification systems utilized by doctors emerge in a social context, and diagnostic categories are subject to social framing or construction. Lay health beliefs too reflect local cultural perspectives, and medical practice involves mediating between expert and lay belief systems. Moreover, medical practice is itself conditioned by the subcultural perspectives associated with the medical profession, its constituent specialisms, and the diverse hospital and community settings where healthcare is provided. The dual nature of medicine as both a scientific and practice-based discipline has resulted in tensions between the art and science of practice, with some doctors putting more weight on clinical judgment based on experience rather than the standardized application of codified knowledge.