👉 An infection is an invasion or colonization of the body by pathogenic microorganisms, such as bacteria, viruses, fungi, or parasites, which can disrupt normal bodily functions and cause disease. When these microorganisms enter the body through various routes—such as the respiratory tract, skin, digestive system, or bloodstream—they multiply and interact with host cells, often triggering an immune response. This interaction can lead to inflammation, tissue damage, and symptoms characteristic of the specific infection. For example, a bacterial infection like pneumonia involves bacteria invading the lungs, while a viral infection such as the common cold involves viruses entering the respiratory system. Understanding infections is crucial for developing treatments and preventive measures to combat diseases and protect public health.
