Have you ever wondered how nurses can be exposed to clients with communicable diseases day after day and not become ill? There are many factors that affect the body’s ability to defend against infection and place some individuals at greater risk of developing an infection. When an infection does occur, early recognition is important to prevent it from spreading within the individual, as well as to others. Protecting people from developing an infection, as well as preventing the spread of infection, is a major concern for nurses. This chapter will discuss the physiology of the inflammation and infectious processes and nursing interventions to prevent the spread of infection.