How do tiny organisms like bacteria and viruses make a large person us ill?

Bacteria and viruses cause illness in individuals regardless of their size. Here's how these tiny organisms can affect a person's health:

1. Bacteria:

a. Toxins: Some bacteria produce toxins (harmful substances) that can cause a range of symptoms, including fever, vomiting, and diarrhea. Bacteria like E. coli and Salmonella are known for releasing potent toxins.

b. Infect Cells: Bacteria can invade and multiply within human cells, leading to tissue damage and inflammation. Infections like tuberculosis and pneumonia are caused by bacteria that directly infect and damage lung tissues.

c. Immune Response: The body's immune system responds to bacterial infections by producing white blood cells and antibodies to fight the invaders. This process can lead to inflammation and symptoms like swelling, redness, and pain.

2. Viruses:

a. Viral Replication: Viruses require living cells to multiply. They enter host cells, hijack cellular machinery, and make copies of themselves, leading to the destruction or malfunction of the infected cells.

b. Cellular Damage: Viral replication can cause damage to host cells, disrupting their normal functions. This damage leads to symptoms associated with viral infections, such as a sore throat, cough, rash, and muscle aches.

c. Overactive Immune Response: In response to viral infections, the immune system can sometimes overreact, leading to an excessive inflammatory response. This can result in high fever, severe body aches, and fatigue.

d. Weakened Immune System: Viruses can also weaken the immune system, making the body more susceptible to secondary infections and complications.

It's important to note that the severity of an illness caused by bacteria or viruses depends on factors such as the type of organism, the person's immune system strength, and the specific strain of the pathogen. Some individuals may experience mild or asymptomatic infections, while others may develop more severe illnesses.