What is a pathogen?

Pathogens are microorganisms—such as bacteria, viruses, fungi, or parasites—that can cause disease in humans, animals, or plants. They invade hosts and disrupt normal bodily functions, leading to various illnesses. Understanding and controlling pathogens is essential for public health, agriculture, and medicine. Preventative measures like vaccination, proper hygiene, and sanitation help reduce the spread of pathogens.