👉 Infection is a biological process where pathogens, such as bacteria, viruses, fungi, or parasites, invade and multiply within a host organism, leading to disease. This invasion can occur through various routes, including inhalation, ingestion, or direct contact. Once inside the body, pathogens can disrupt normal cellular functions, trigger immune responses, and cause symptoms ranging from mild irritation to severe illness. The infection process involves the pathogen's ability to adhere to and penetrate host tissues, evade or manipulate the immune system, and replicate. The body's defense mechanisms, including innate and adaptive immunity, work to combat the infection, but if the pathogen overcomes these defenses, it can lead to infection, characterized by inflammation, tissue damage, and potentially systemic complications depending on the pathogen and the site of infection. Understanding the regions where infections occur—such as the respiratory tract, gastrointestinal system, skin, or bloodstream—is crucial for developing targeted treatments and preventive measures.
