Bacterial Infection: Symptoms, Causes, and Treatments

Close up view of bacteria at Stephen E. Fry Laboratory Services

Bacterial infections are a common occurrence across the globe. In fact, there are an estimated 2.8 million serious bacterial infections each year in the United States. This doesn’t even include minor infections.

Luckily, a bacterial infection is usually not a serious issue. Some bacteria are even good for you. But, you should still be aware of the signs of a bacterial infection and the treatment options available to you.

In this guide, we’ll explore everything you should know about the symptoms, causes, and treatments of these common infections.

What Is a Bacterial Infection?

There are many different types of infections. These include bacterial, viral, fungal, and parasitic. The classification of an infection depends on its cause.

Bacteria is a microscopic organism that can generally survive on its own, either inside or outside the human body. Most of these bacteria aren’t dangerous or harmful. In fact, millions of bacteria live on and inside your body every day.

However, some bacteria can infect the body, causing an immune response to get rid of the bacteria. Bacterial infections can affect virtually any part of the body and can range from severe to mild.

Some common bacterial infections you may have heard of include:

  • Urinary tract infection (UTI)
  • Ear infection
  • Strep throat
  • Whooping cough

Generally, bacteria enter the body through an opening in the skin. This includes cuts or other kinds of wounds. Bacteria can also enter through your airway, which can lead to infections in the throat and lungs.

Types of Bacterial Infections

How severe bacterial infections are can vary widely. It usually depends on the type of bacteria that is infecting and the location of the infection.

Bacterial infections can range from strep throat and ear infections to potentially life-threatening conditions such as encephalitis or meningitis.

Some common bacterial infections you may come across include:


Salmonella is most commonly associated with food poisoning. One of the most common ways to get salmonella is by eating undercooked poultry, such as chicken or turkey.

Salmonella symptoms include upset stomach and severe nausea, diarrhea, and vomiting.

Nontyphoidal salmonellae bacteria are responsible for salmonella infections. This particular bacteria lives in the digestive tract. It can is common in both humans and other animals.

E. Coli

Another bacterial infection that is closely related to food poisoning is Escherichia coli, or E. coli for short. This infection also results in an upset stomach and various digestive symptoms, such as vomiting and diarrhea.

Usually, E. coli infections will improve on their own. However, some infections can be severe or life-threatening.

Contaminated foods spread E. coli bacteria. This often includes unwashed or uncooked vegetables, such as lettuce.


Tuberculosis is a lung infection. It is also a highly contagious disease.

Mycobacterium tuberculosis bacteria is the cause of tuberculosis. This disease must have swift treatment in a quarantined setting to prevent spreading.

Methicillin-Resistant Staphylococcus Aureus (MRSA)

MRSA bacteria is incredibly dangerous due to its antibiotic resistance. It is particularly harmful to those with compromised immune systems.

Treatment is often aggressive. It includes high doses of steroids and intravenous (IV) antibiotics.

Clostridium Difficile (C. diff)

C. diff is generally harmless bacteria that are commonly found in your intestines. However, the overgrowth of this bacteria can lead to a more harmful infection.

Overgrowth is traditionally caused by the over-usage of antibiotics or having a weakened immune system. Symptoms of C. diff infection include inflammation in the colon and persistent diarrhea.

Bacterial Pneumonia

Pneumonia is a lung infection. Multiple bacteria may be the cause of pneumonia. These include Pseudomonas aeruginosa, Klebsiella pneumoniae, or Streptococcus pneumoniae.

The pneumonia infection spreads through air particles when an infected person coughs or sneezes, no matter which bacteria is the cause.

Bacterial Vaginosis

When the normal bacterial flora of the vagina becomes imbalanced, the result is bacterial vaginosis. Bacterial vaginosis is an infection of the vagina.

Symptoms of bacterial vaginosis include painful urination, itchiness, and irregular vaginal discharge.

Heliobacter pylori (H. pylori)

H. pylori bacteria leads to an infection of the stomach. It can cause stomach ulcers, inflammation of the stomach, or chronic gastritis.

This type of infection is most common in those with high levels of stomach acid and those who smoke.


Sexually transmitted diseases are also sometimes the result of a bacterial infection. Gonorrhea is one such infection. The bacteria Neisseria gonorrhoeae causes this infection.

Symptoms can vary between males and females. In some cases, there may not be any symptoms at all. Regular STD screenings can help detect gonorrhea so you can seek out appropriate treatment.

Vibrio Vulnificus

Vibrio vulnificus is a bacteria that lives in seawater. It is usually found in warmer waters.

This bacteria is a “flesh-eating bacteria.” It can be quite harmful, especially for those with open cuts or wounds or those with weakened immune systems.

You should always heed guidance from your local beach to ensure vibrio vulnificus is not present. You should also avoid going into the ocean if you have any open wounds.

Bacterial Infection Symptoms

Symptoms may vary depending on the type of bacterial infection you have and the area of the body it affects. However, there are some symptoms that are common among most bacterial infections.

These symptoms include:

  • Fatigue or extreme tiredness
  • Headache
  • Nausea or vomiting
  • Swollen lymph nodes in the neck, armpit, groin, or elsewhere
  • Fever
  • Pus-filled or inflamed wounds

The Timing of Symptoms

All bacterial infections have an “incubation period.” This is the time it takes for the bacteria to truly infect the body. Usually, symptoms will not appear until the incubation period has passed.

In some cases, infections will become more severe over time due to this period of incubation. This can cause infections to progress rapidly or develop slowly, depending on the type of bacteria.

When Should I See a Doctor?

While most bacterial infections are common, you should still see a doctor when symptoms begin to appear. Many bacterial infections will require treatment to prevent them from getting worse. You should always seek medical attention if you think you may have a bacterial infection.

More serious symptoms may signal that it’s definitely time to pay your doctor a visit. These symptoms include:

  • A persistent or productive cough
  • Unexplained swelling or redness of the skin
  • Blood in urine, vomit, or stool
  • Difficulty breathing
  • Frequent vomiting
  • Troubling holding down liquids
  • Severe headache or stomach pain
  • A cut or burn with redness, inflammation, or pus

Diagnosing a Bacterial Infection

Your doctor can determine if you have a bacterial infection based on a few different clues. These might include:

  • The pattern of symptoms
  • Location of the infection
  • Timing of symptom progression
  • Severity of symptoms

Usually, they will perform testing to confirm their suspicions before they administer treatment. Testing usually consists of collecting a sample of pus or other liquid to send to a laboratory. Swabs of the ear, nose, or throat are also occasionally used as samples.

Urine samples help to detect infections in the bladder or kidney. Stool samples can help determine if there is a bacterial cause behind any digestive distress.

Blood Tests

A blood test is sometimes a useful tool for detecting bacterial infections. Usually, the white blood cell count will be higher in those who are fighting an infection, as they are a critical part of the immune system response.

Sometimes, doctors may order a complete blood count (CBC) with differential to determine which types of white blood cells are being overproduced.

This can give doctors clues as to which type of infection you may have.

Imaging Studies

Some bacterial infections also cause the formation of a bacterial abscess. A bacterial abscess is an enclosed, pus-filled area that may develop inside the body.

If your doctor suspects that you may have a bacterial abscess near or inside your organs, they may order imagining tests, such as an X-ray.

X-rays are also common for the diagnosis of certain infections, such as pneumonia.

Complications of Bacterial Infections

If you leave a bacterial infection untreated, it can lead to some pretty serious complications.

One life-threatening complication is known as sepsis. Sepsis is a serious infection of the blood. It can lead to septic shock, organ failure, and death if it is not quickly and aggressively treated.

Sepsis is a medical emergency. If you notice any of the following symptoms, you should seek immediate medical care:

  • Fever
  • Chills
  • Rapid breathing and heart rate
  • Extreme tiredness
  • Headaches
  • Uncontrolled shaking

How To Treat a Bacterial Infection

Antibiotics are the most common and effective bacterial infection treatment. Once your doctor has determined the cause of your infection using tests such as DNA sequencing, they will administer the appropriate dosage and type of antibiotics.

Antibiotics work by either killing the bacteria or preventing them from multiplying. This gives your immune system a chance to tackle the infection itself.

Some antibiotics only work on certain infections. Others will work on many different types of bacteria. These are known as broad-range antibiotics.

Be aware that many bacteria are developing antibiotic resistance due to the over-prescription of medications. Therefore, your doctor may only administer antibiotics in the case of a serious bacterial infection.

Supportive Care

In some cases, infections may cause dehydration, fever, pain, swelling, or coughing. Your doctor may prescribe supportive care, such as anti-inflammatory medication, anti-fever medication, or hydration supplements.

If you’ve become severely dehydrated, you may need an IV. Consult with your doctor throughout your treatment, so they can monitor the progression of your infection.

Take care to maintain a healthy lifestyle to further boost your immune system’s fighting power.

Drainage of Abscesses

When a bacterial abscess forms, you may have to have surgery. If the abscess is superficial, or above the skin, this is a simple procedure.

Deeper abscesses, such as those located in the brain or intestines may require more serious surgical intervention.

Are Bacterial Infections Preventable?

A bacterial infection is generally highly contagious. The best ways to avoid a bacterial infections include:

  • Frequently washing your hands
  • Covering your mouth or nose when coughing or sneezing
  • Avoid sharing cups, drink bottles, and unwashed eating utensils
  • Immediately cleaning any cuts or burns and following up with the appropriate after-care

In general, staying clean is the best way to prevent bacterial infections.

How Do I Know If an Infection Is Bacterial or Viral?

Bacterial and viral infections have many similar symptoms. They also have similar causes.

Both bacterial and viral infections are the result of microscopic objects known as microbes. Microbes can cause things such as:

  • Acute infections, which do not last long
  • Chronic infections, which can last months to years
  • Latent infections, which may not present symptoms until much later than the initial infection

Both bacterial and viral infections can also lead to more serious diseases. So what’s the difference between bacterial vs. viral infection?

Well to start, viruses are much smaller. Unlike bacteria, most viruses are harmful to the body. In some cases, viruses may even target bacteria.

If you think you may have a bacterial or viral infection, consult your doctor. They can perform tests such as DNA sequencing, culture tests, or even a biopsy to determine the cause and administer the appropriate treatment.

Keep Your Body Standing Strong

Usually, a bacterial infection is nothing to worry about. And now that you know the symptoms and treatments, you’ll be better prepared should you ever find yourself with one. The most important thing is not to panic, and to allow your doctor to administer the appropriate treatment.

Contact our office if you have any further medical questions or inquiries. Your health is our top priority.

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