👉 Infection occurs when a pathogen, such as a virus, bacteria, fungus, or parasite, enters a host's body and begins to multiply or cause disease. This process starts when the pathogen breaches the body's natural barriers, like the skin or mucous membranes, and then invades tissues or organs. The pathogen can replicate within host cells, produce toxins that damage tissues, or trigger an immune response that leads to inflammation and symptoms of illness. For example, a bacterial infection might cause fever and swelling, while a viral infection could result in respiratory symptoms like coughing and congestion. Effective treatment often involves targeting the pathogen directly or bolstering the body's defenses to combat the infection.
