Why You Probably Don't Need Antibiotics for a Cold or Flu

You've been sick for a few days now and think you might have a respiratory infection. Your throat is scratchy and sore. You're sniffling and sneezing, and your eyes are teary. You feel achy, fatigued, and miserable. Should you go to your physician and request an antibiotic?

Going to see your physician when you feel sick is always a good idea; however, chances are that you don't need that antibiotic.

What Are Antibiotics?

Antibiotics can kill bacteria (bacteriocidal) or slow their ability to multiply (bacteriostatic). The first antibiotics discovered were natural products of molds and other organisms. Infections that once killed untold millions could finally be cured and came to be considered minor and treatable. Newer, laboratory-synthesized drugs have joined the ranks of antibiotics effective against a wide variety of bacteria.

What Are Bacteria?

Bacteria are microscopic organisms found throughout nature. They can live inside or outside the human body; some are even beneficial and necessary for good health. Others, however, are "pathogenic" and they cause infection and illness. These bacteria are responsible for a whole host of human respiratory infections, including some sinus and ear infections, certain kinds of pneumonia, and strep throat.

What Are Viruses?

Viruses are even tinier than bacteria. When you get a viral infection, viruses invade your body's cells, using your cells' machinery to help make more and more viruses. These viruses are responsible for the flu, the common cold and many types of sore throats, coughs, ear infections, bronchitis, and even pneumonia.

Unlike bacteria, viruses are not killed by antibiotics.

Why Can't I Take an Antibiotic Just in Case?

There are big problems with the cavalier use of antibiotics. When bacteria are exposed to an antibiotic, while many are killed, subsequent generations of others may develop characteristics that allow them to resist being killed. While the antibiotic kills off the weakest bacteria, antibiotic resistance allows the stronger, resistant bacteria to continue multiplying because it has developed the ability to beat the drugs designed to kill it off.

The eventual result can be "superbugs," which refers to when bacteria become resistant to several types of antibiotics. These are very hard to kill and may only succumb to extremely powerful antibiotics. In fact, the Centers for Disease Control and Prevention estimates that at least 2 million people are infected by these superbugs every year in the U.S., with at least 23,000 people dying from them. Such antibiotics pose a greater risk of significant adverse effects that may require hospitalization and are much more costly. Some superbugs go on to cause devastating and even fatal infections that are incurable with current antibiotics.

Examples of Antibiotic-Resistant "Superbugs"

  • Carbapenem-resistant Enterobacteriaceae (CRE)
  • Methicillin-resistant Staphylococcus aureus (MRSA)
  • ESBL-producing Enterobacteriaceae (extended-spectrum β-lactamases)
  • Vancomycin-resistant Enterococcus (VRE)
  • Multidrug-resistant Pseudomonas aeruginosa
  • Multidrug-resistant Acinetobacter

How Can I Tell If My Symptoms Are Due to a Virus or Bacteria?

This distinction can be tricky; that's why it's worth a visit to your doctor.

A few pointers:

  • Most virally caused colds and other upper respiratory infections will produce a wide variety of symptoms, such as a sore throat, sniffles, cough, and achiness.
  • Bacterial infections often cause a more focused area of misery, such as a severely painful ear or an extremely sore throat.
  • Some of the signs (like thick, green mucus) used to be thought of or suggested the presence of a bacterial infection, but this is no longer believed to be accurate.
  • Viral illness usually abates after a week. Illnesses that last more than 10 days or that grow suddenly worse after five to seven days may have evolved into a bacterial infection.
  • People with underlying lung problems (such as asthma or chronic obstructive pulmonary disease) or other chronic illnesses may be more prone to bacterial infections and should seek a professional opinion sooner.

How Can I Help Prevent Superbugs?

  • Practice good hand-washing to avoid becoming ill or passing an illness on to others.
  • Get a yearly flu vaccination.
  • If you do need an antibiotic, make sure you take it as directed; don't stop the medicine just because you begin to feel better. Not taking the entire prescription may allow resistant bacteria to thrive and not be completely killed off.

A Word From Verywell

If you become ill, talk with your physician about whether your illness is more likely caused by a virus or bacteria. Don't insist on an antibiotic; ask your physician why you do or do not need one. Lastly, keep in mind that prescription medications are never meant to be shared. Don't ever take someone else's antibiotic, and don't give yours to anyone else either.

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Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Antibiotic/antimicrobial resistance (AR/AMR). About microbial resistance.

  2. Centers for Disease Control and Prevention. Viruses or bacteria: What's got you sick? Nov. 16, 2017.

  3. Centers for Disease Control and Prevention. Antibiotic/Antimicrobial Resistance (AR/AMR). Protect yourself and your family.

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