How do bacteria and viruses cause diseases?

Viruses cause disease by damaging cells and cell operation. They infiltrate, alter, and eventually destroy your organs one cell at a time. As the various tissues get more and more damaged, they malfunction and cause symptoms.





Bacteria usually cause sickness by releasing toxins wich interfer with your bodily processes. Sometimes these poisons also damage your tissues and sicken you in much the same way as a virus.





Most of what we think of as "being sick" is not actually the pathogens fault, it is the bodies attempt to cleanse itself that causes our symptoms. Like a fever, that is a body response in an attempt to burn out the invader.

How do bacteria and viruses cause diseases?
Agree with juicy_wishun. Also, bacteria reproduces in your body when it finds ideal thriving conditions. Usually moist dark place. Viruses, on the other hand, inject their own DNA into your cells. That causes the cell to produce more viruses. The period of time it takes for the cell to produce and release the virus can vary. Retroviruses, such as HIV, inject their own rNA into the host cell's DNA. Antibiotics work only on bacteria. Antivirals usually only reduce the viral load as they are ineffective in killing the viral DNA inside host cells. Fungi are also difficult to destroy, because when presented with an unsuitable environment, the fungus DNA becomes incapsulated and can survive for extrememly long periods of time until more suitable thriving conditions present themselves.