Staying Healthy: The Science Behind Germs

The human body is an amazing machine. Many things go on inside of our bodies every day that keep us breathing and moving. Our heart pumps blood. Our stomach and intestines digest food. Our brain sends signals to all of the other parts to keep them working. Most of the time, everything works in harmony to keep us in good health. Sometimes, though, the body is invaded by tiny organisms that make us sick. These little invaders are called germs.

Germs are very, very small. They are so small that the naked eye cannot see them. An instrument called a microscope must be used to see them. We can’t see them sneak into our bodies, but we can tell that some of them are there because they make us feel sick.

There are four main types of germs: bacteria, viruses, fungi, and protozoa. Although they are all germs, they each have their own characteristics.


Bacteria are a type of germ. They are all around us and even on our skin and inside of our bodies. Bacteria are single-celled, and they do not have a nucleus like other types of organisms. If you looked at bacteria in a microscope, you would see that they come in several different shapes, such as spirals, spheres, and rods.

Bacteria can cause infections such as ear infections, tonsillitis, strep throat, and pneumonia. Some bacteria are harmless, though, and some bacteria are even helpful. Helpful bacteria live in our digestive system and help us use the food we eat for energy and discard the rest as waste. Bacteria are also useful to scientists, as they use them to make some medicines.


Viruses are another type of germ that can make us sick. Viruses have to be inside a living thing to be active. Their host could be a person, an animal, or a plant. They can survive on surfaces such as keyboards and doorknobs. They can also float in the air and live in water. It is once they get inside a host that they cause problems. Once they get inside a host, they use it to make more viruses. They cause illnesses such as the flu and chicken pox.


Fungi are multi-celled organisms. Fungi can be found in the air as well as on land and in water. Fungi can cause issues within the body, such as athlete’s foot. Athlete’s foot is an itchy rash that people often get in between their toes. Like bacteria, fungi can also be helpful. They are used to make medicine such as penicillin, an antibiotic that fights infection. Some fungi are food: Mushrooms are common fungi that we eat. The yeast used to make bread is also a type of fungus that we encounter almost every day.


Protozoa are germs that love water and moisture. Protozoa are single-celled organisms. There are more than 30,000 different species of protozoa. Protozoa can cause some serious problems in our intestines, such as nausea and diarrhea.

Prevention and Protection

Staying in good health means preventing germs from getting inside of us. Often, germs will get on our hands, and then they get inside of us when we touch our lips or nose. The very best way to prevent that from happening is to wash our hands well and often: Soap and water can kill most germs. To wash your hands properly, use warm water and soap and rub the soap all over your hands for at least 15 seconds. Wash your hands before you eat or cook something, after a bathroom visit, after being outside, and after you touch an animal.

Vaccines are another thing we use to protect ourselves from germs. Children are usually on a vaccination schedule and go to the doctor to get them. Getting vaccinations isn’t always that much fun, but they are an important weapon against germs and diseases. Eating healthy foods, getting enough exercise, and getting plenty of sleep are also important to help you fight off germs. Everyone gets sick sometimes, but the more you know about germs, the better prepared you will be to defeat them.

Online Master of Health Administration