A pathogen is an organism that causes disease.
Your body is naturally full of microbes. However, these microbes only cause a problem if your immune system is weakened or if they manage to enter a normally sterile part of your body.
Pathogens are different and can cause disease upon entering the body.
All a pathogen needs to thrive and survive is a host. Once the pathogen sets itself up in a host’s body, it manages to avoid the body’s immune responses and uses the body’s resources to replicate before exiting and spreading to a new host.
Pathogens can be transmitted a few ways depending on the type. They can be spread through skin contact, bodily fluids, airborne particles, contact with feces, and touching a surface touched by an infected person.
There are different types of pathogens, but we’re going to focus on the four most common types: viruses, bacteria, fungi, and parasites.