👉 Infection refers to the process by which a pathogen, such as a virus, bacterium, fungus, or parasite, enters and establishes itself within a host organism, leading to disease. This occurs when the pathogen breaches the body's natural barriers—like the skin or mucous membranes—and begins to multiply or cause damage to cells, tissues, or organs. The immune system then responds to combat the invader, but if the infection is severe or the host's defenses are compromised, it can result in illness. Infections can be acute, lasting for a short time, or chronic, persisting over an extended period. Common examples include the flu (viral), strep throat (bacterial), and tuberculosis (fungal). Understanding infection is crucial for developing treatments and preventive measures to protect health.
