Bacteria vs. Viral Infections

When you are sick, it may be tough to know what is causing it.  All you want to do is get well. However, in order to treat what’s making you sick, we need to know.

Bacterial infections are caused by bacteria and can be treated with antibiotics.  Viral infections are caused by viruses and need to be treated with lots of rest, lots of fluids, and possibly a humidifier and a saline aspiration for the nose.

If you have a low grade fever, you are achy, it most likely a viral infection that will last 2-3 days.  If you have high fever, and swelling, you most likely have a bacterial infection. If your illness persists, you need to see a doctor.


Bacteria are relatively complex, single-celled creatures with a rigid wall and a thin, rubbery membrane surrounding the fluid inside the cell. They can reproduce on their own. Fossilized records show that bacteria have existed for about 3.5 billion years, and bacteria can survive in different environments, including extreme heat and cold, radioactive waste, and the human body.

Most bacteria are harmless, and some actually help by digesting food, destroying disease-causing microbes, fighting cancer cells, and providing essential nutrients. Fewer than 1% of bacteria cause diseases in people.


Viruses are tinier: the largest of them are smaller than the smallest bacteria. All they have is a protein coat and a core of genetic material, either RNA or DNA. Unlike bacteria, viruses can’t survive without a host. They can only reproduce by attaching themselves to cells. In most cases, they reprogram the cells to make new viruses until the cells burst and die. In other cases, they turn normal cells into malignant or cancerous cells.

Also unlike bacteria, most viruses do cause disease, and they’re quite specific about the cells they attack. For example, certain viruses attack cells in the liverrespiratory system, or blood. In some cases, viruses target bacteria.

Bacteria-vs-Virus diagram

Diagnosis of Bacterial and Viral Infections

You should consult your doctor if you think you have a bacterial or viral infection. Exceptions include the common cold, which is usually not life-threatening.

In some cases, it is hard to determine the cause of an infection because many ailments — including meningitis, pneumonia, and diarrhea — can be caused by either bacteria or virus. Your doctor can often pinpoint the cause by listening to your medical history and doing a physical exam.  If necessary, your doctor can order a blood or urine test to help confirm a diagnosis, or a “culture test” of tissue to identify bacteria or virus.

Treatment of Bacterial and Viral Infections

Viral infections have to run their course.  Over the counter medicines can alleviate the symptoms and help you feel better.  As mentioned earlier, lots of rest and fluids help.

Antibiotics are used for bacterial infections.  Unfortunately, the overuse of antibiotics has made many bacteria resistant to antibiotics.

Antibiotics are not effective against viruses, and many it is highly recommended that antibiotics are not prescribed unless there is clear evidence of a bacterial infection.

If your doctor concludes you have a viral infection, don’t be disappointed if they do not give you antibiotics.  It is the right move.