👉 Ch: Infection, in medical terms, refers to the process by which a pathogen—such as bacteria, viruses, fungi, or parasites—enters and establishes itself within a host's body, leading to disease. This occurs when the pathogen breaches the body's natural barriers, such as the skin or mucous membranes, and begins to multiply or cause damage. The infection can then spread locally or systemically, affecting various organs and systems. For example, a bacterial infection like pneumonia involves pathogens entering the lungs, while a viral infection like influenza affects the respiratory tract. The body's immune response plays a crucial role in fighting off the infection, but if the pathogen is highly virulent or the host's defenses are compromised, the infection can lead to illness or even severe complications.
