What are Bacterial Infections?

Authored by The Rx Advocates, / Medically Reviewed by Dr. Conor Sheehy, PharmD, BCPS


Bacteria live in and on the human body in many forms. Good bacteria act as a line of defense against pathogens that want to cause illness. It also helps to keep the immune system balanced.

When harmful bacteria flourish, it can cause infections and lead to diseases. Bacterial infections can take on different forms. How the symptoms show up depends primarily on which area of the body is affected.

The proper diagnosis comes from understanding the causes, symptoms, and types of bacterial infections. Only then can an effective treatment and the appropriate medication be given.

What are Bacterial Infections?

Bacterial infections occur when harmful bacteria enter the body. The germs then multiply and cause the body to react.

Bacteria can be transmitted through:

  • Cuts or wounds
  • Tears in the skin
  • Insect bites
  • Surgery sites
  • Respiratory system (such as inhaling germs from the air that is breathed)
  • Urinary tract
  • Dental wounds (i.e., abscesses)
  • Bed sores (like among the elderly or those requiring care assistance)

Infections can also occur through close contact with an infected person. Kissing or touching can transfer germs. This creates an opportunity for the bacteria to enter the second host.

Bacterial Infections and Viruses: What’s the Difference?

Those experiencing symptoms may wonder if their condition is bacterial or viral.

Bacterial infections may last two weeks or longer, with a high fever that gets worse instead of better.

Viruses may respond to antiviral meds within the first few days of sickness. The fever that’s experienced gets better instead of worse, and rarely is the patient in danger.

Steps Toward Infection Prevention

Some basic measures in everyday life can help prevent many infections. While not fail-proof, the following steps can cut the possibilities of disease:

  • Frequent handwashing (especially if working in direct care facilities or hospitality services)
  • Cover sores after thorough cleaning (avoid picking scabs from wounds)
  • Keep the mouth and nose covered when coughing and sneezing
  • Don’t share toiletries (i.e., razors or toothbrushes) with other people
  • Maintain a balanced diet of nutritious foods (to strengthen the immune system)

General Symptoms

Specific types of bacterial infections have distinctive symptoms. However, there are some general symptoms to watch for as well, including:

  • Pain (worsening or sudden)
  • Fever
  • Swollen glands
  • Excessive sweating
  • Fatigue
  • Flushed, swollen, or sore skin
  • Headache
  • Stomach upset (including nausea, vomiting, diarrhea, or gastrointestinal pain)

Symptoms Specific to Infection Location

Many of the symptoms that develop are infection-specific. Here are some bacterial infections that occur in various body locations.

Abdominal Infections

People with stomach upset may be experiencing a gastrointestinal infection. Some of the signs and symptoms associated with this include:

  • Vomiting
  • Nausea
  • Abdominal pain
  • Tender belly
  • Decreased appetite
  • Increased bowel activity
  • The urgency to have a bowel movement (whether or not there is anything there)
  • Diarrhea (sometimes has blood, is liquidy, and is loose)
  • Feeling feverish
  • Colon inflamed

Ear Infections

The ear consists of three parts, each of which can become infected. The inner, middle, or outer ear may be affected by bacterial infections. They will then show signs of any of the following symptoms:

  • Rapid onset
  • Full feeling in the ear
  • Draining of fluid from inside the ear
  • Feeling pressure and pain in the ear
  • Feverish
  • Low energy
  • The area around the ear is irritated and itchy
  • Scaly ear skin
  • Loss of hearing

Lower Respiratory Infections

The lower part of the respiratory system involves the trachea, bronchi, and lungs. These connect the trachea (windpipe) to the bronchi (airways) to the lungs.

Bacterial pneumonia is a form of lower respiratory infection that can occur. Signs of this illness include:

  • Mucusy cough (with a bloody, green, or yellow color)
  • Breaths that are fast and not deep
  • Pain in the chest (when deeper breaths or coughs cause sharper stabs of pain)
  • Feverish
  • Short of breath
  • Chills
  • Unusual deep fatigue
  • Drop in energy
  • Nauseousness with vomiting (especially in children)
  • Mental confusion (especially in elderly adults)

Upper Respiratory Infections

The respiratory system is essential to the function of the body. The upper respiratory tract is the nasal and sinus cavities found in the skull.

It is called sinusitis when a bacterial infection or a virus enters this space. This term covers infection as well as inflammation in the upper respiratory tract.

Symptoms may include:

  • Nasal congestion and runny nose
  • Headache
  • Postnasal drip (when mucus fluid is dripping at the back of the throat)
  • Painful pressure on the face
  • Sore throat
  • Coughing
  • Unusual odor to the breath

Skin Infections

A break in the skin acts as an easy entry point into the body for bacteria. Many things can cause these breaks, such as surgeries or wounds.

Skin infections that can commonly occur are:

  • Cellulitis: Bacteria penetrating the deep layers of skin is called cellulitis. It usually affects one limb at a time. Symptoms may include:
    • Skin is hot to the touch
    • Swelling and pain in the affected area
    • Pitting in the skin that looks like an orange peel
    • Oozing and pus-filled blisters
    • Lymph nodes swelling
    • Feverish (with chills)
    • Difficulty healing wounds
  • Impetigo: When a bacterial infection impacts the face and hands, this is impetigo. It may appear in other areas as well, but these symptoms are sure signs of this condition:
    • Sores that itch and have leaky fluids draining
    • With time, crusted, yellowed scabs
    • Swollen lymph nodes
    • Feverish
    • General fatigue and lack of energy

Throat Infections

The bacterial infection that attacks the throat and tonsils is termed strep throat.

The bacteria responsible for this infection is Streptococcus. Children and teens are more likely to develop this condition. Although, anyone at any age may be affected.

Strep throat symptoms and signs can include:

  • Painful to swallow
  • Sore throat
  • The top of the mouth has small red-colored spots
  • Tonsils appear swollen and discolored
  • Swelling of the lymph nodes on the neck front
  • Feverish

Vaginal Infections

Sometimes, bacteria can enter the body through the vagina. Bacterial vaginosis (BV) is commonly diagnosed among females from 15 to 44 years of age.

Symptoms of this bacterial infection include:

  • Discharged fluid (white or gray-colored)
  • Painful, itchy, and burning sensation on the inside of the vagina
  • Outer vaginal itchiness
  • The feeling of burning during urination
  • Unusual odor (heavy, fish-smell)


Determining a diagnosis of a bacterial infection will need some tests and procedures. Depending on the symptoms, a doctor may order:

  • Blood tests (possibly to check the WBC or white blood cell count)
  • Urinary testing (from a urine sample)
  • Throat cultures (taken through a gentle swabbing of the back of the throat)
  • Samples of stool (taken from a bowel movement to test for bacteria)
  • Lumbar puncture (spinal tap)
  • X-ray (often used to determine if a patient has pneumonia)
  • Biopsy (exam of a tissue sample)


The typical treatment for bacterial infections is a course of antibiotics. Specific antibiotics target individual conditions. Therefore, determining the exact illness is essential for healing.

Besides antibiotics, treatments may include:

  • Cough suppressants (for respiratory illnesses)
  • Hydration (to prevent dehydration, especially if experiencing a loss of appetite)
  • Proper Nutrition (to act as fuel to strengthen the immune system)
  • Rest (to give the body the chance to rejuvenate)
  • Over-the-counter pain medications (like NSAIDs to fight against inflammation)
  • Ointments (for skin ailments)


There are different antibiotic groupings considered effective against bacterial infections. They include:

  • Aminoglycosides
  • Carbapenems
  • Cephalosporins
  • Glycopeptides
  • Lincomycins
  • Macrolides
  • Penicillins
  • Quinolones
  • Sulfonamides
  • Tetracyclines

Among those groupings, the following antibiotics commonly are a part of a treatment plan:

Also, some OTC treatments are available. The following ointments are effective antibiotic options for treating bacterial skin infections.

  • Neosporin
  • Neosporin Plus Pain Relief
  • Polysporin
  • Triple Antibiotic Ointment

The Rx Advocates Can Help with Costs

Good medicine shouldn’t have to be out of reach because of cost. Let The Rx Advocates help match you with prescription advocacy programs.

Contact us today if you find paying for the medicines you need challenging. We are ready to help you get the care you deserve!

  1. National Center for Health Research. Bacteria: the Good, the Bad, and the Ugly. 2022. Available at: center4research.org.
  2. NIH. Bacterial Infections: Overview. August 26, 2008. Available at: ncbi.nlm.nih.gov.
  3. Medical News Today. Bacterial vs. Viral Infections: What is the Difference? May 24, 2022. Available at: medicalnewstoday.com.
  4. Harvard Health Publishing: Harvard Medical School. How to Prevent Infections. February 15, 2021. Available at: health.harvard.edu.
  5. Sepsis.org. Bacterial Infections. January 24, 2022. Available at: sepsis.org.
  6. Medical News Today. Bacterial Infections: Symptoms by Location. August 29, 2020. Available at: medicalnewstoday.com.
  7. Mayo Clinic. Infectious Diseases: Diagnosis. February 18, 2022. Available at: mayoclinic.org.
  8. Drugs.com. Augmentin. April 4, 2022. Available at: drugs.com.
  9. Drugs.com. Avelox. March 2, 2022. Available at: drugs.com.
  10. Drugs.com. Bactrim. October 18, 2021. Available at: drugs.com.
  11. Drugs.com. Cipro. August 11, 2020. Available at: drugs.com.
  12. Drugs.com. Cleocin. July 22, 2022. Available at: drugs.com.
  13. Drugs.com. Flagyl. October 20, 2021. Available at: drugs.com.
  14. Drugs.com. Keflex. February 5, 2021. Available at: drugs.com.
  15. Drugs.com. Levaquin. February 4, 2022. Available at: drugs.com.
  16. Drugs.com. Zithromax. November 19, 2021. Available at: drugs.com.
Call Now Button