What determines the severity of disease manifestation?

cbse
cbse-class-9-science
why-do-we-fall-ill

#1

What determines the severity of disease manifestation?
Answer:
The number of disease-causing microbes in the body decide the severity of disease manifestation. If the number of microbes is very small, the disease manifestations may be minor and even go unnoticed. But if the number of microbes is large, the disease can be severe. In fact if the number of microbes is very large, the disease can even be fatal. Our immune system is a major factor that determines the number of microbes surviving in the body.