The course introduces students to the concept of disease and various classifications of diseases. It also introduces students to the historical antecedent of the study of disease. It covers communicable and non-communicable diseases. It also equips students with the knowledge of disease theories as well as factors promoting disease occurrence at personal, community, national and global levels or among specific population. The course also lays emphasis on emerging diseases of public health interest such Neglected Tropical and Zoonotic Diseases. It will cover how they can be prevented at all levels of occurrence.