This document summarizes different types and stages of tuberculosis infection and disease. It describes primary tuberculosis occurring in previously unexposed individuals, which may lead to fibrosis and healing or progressive primary disease. It also describes secondary or reactivation tuberculosis occurring in sensitized hosts, which typically involves the lung apices and may progress to cavitary lesions if not treated properly. The document discusses the pathology, microbiology, immunology and clinical manifestations of tuberculosis at different stages.