First Aid Infections How Can I Tell If My Infection Is From a Virus or Bacteria? What's the Difference? By Rod Brouhard, EMT-P Rod Brouhard, EMT-P Verywell Health's Facebook Verywell Health's LinkedIn Verywell Health's Twitter Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients. Learn about our editorial process Updated on May 09, 2022 Medically reviewed by Michael Menna, DO Medically reviewed by Michael Menna, DO Michael Menna, DO, is a board-certified, active attending emergency medicine physician at White Plains Hospital in White Plains, New York. Learn about our Medical Expert Board Print As you may know, bacterial infections can be treated with antibiotics. However, antibiotics are often overused and authorities now caution against using them for things like viral infections, which aren't affected by antibiotics. So, how can you tell the difference? Peter Dazeley / Photographer's Choice / Getty Images You can't. At least, you can't without help from a healthcare provider. You may be tempted to try diagnosing your own infection at home without seeing the doc, either because you want to save money or time. You might figure if it's a viral infection and you can't get any help from antibiotics, what's the reason for going to the healthcare provider? There is no reason for everyone with a common cold needs to go running to the healthcare provider, but there are a couple of problems with making your decision based whether or not you think it's a viral infection or not. Depending on the type of viral infection, there may still be medications that can help. The medicines specifically targeting viruses are called antivirals. They're not used as often as antibiotics, but in some cases they help a lot. There's absolutely no way to tell if an infection is caused by bacteria without a test. There are some telltale signs that help point us in the right direction, but unless it's life-threatening, most docs will take a sample before doling out antibiotics. The sample taken depends on the suspected infection, and can include a blood sample, throat culture, skin swab, or more. The desire to diagnose at home is human nature, but rather than wondering if the infection is viral or bacterial, instead focus on whether you need to see a healthcare provider. Here are some good rules of thumb when trying to decide whether to see the doc. Make an appointment if you see any of the following: Dehydration. Mom always wants to bring you chicken soup when you're sick. The healthcare provider always tells you to drink clear fluids (chicken broth counts). Staying hydrated helps you thin out the mucus your body is producing. While your immune system fights infection -- of either type -- it uses mucus to carry away the virus or bacteria from the body. If the mucus is too thick, say from dehydration, the infection could get worse. Indeed, bacteria can take hold in mucus that was originally produced while your body was fighting a virus. Shortness of breath. If an infection is attacking your lungs or airways, it's time to see the doc. Pneumonia or asthma with bronchitis can become life-threatening if not treated promptly and appropriately. Weakness, confusion or fainting. Combined with the usual suspects of fever, chills and body aches, any version of fatigue or weakness is a sign of serious infection. Suddenly getting worse. If you're plugging along, especially if it feels like you might be beating this thing, and suddenly you feel worse, it's probably time to see the healthcare provider. Sometimes one infection opens the door to another. Like I said already, mucus produced by viral infections can sometimes be a great place for bacteria to grow. Kids with fevers. Fevers are a common part of viral illnesses in children -- most of which improve with supportive care (fluid, medicine to bring down the fever, and perhaps a big dose of TLC). Talk to your healthcare provider about situations that might require a visit to the healthcare provider. You may have heard that green mucus or a wet cough is a sign of a bacterial infection. It might be true that green snot is a sign that something is growing in there, but it doesn't exclude the possibility that something else caused the infection in the first place. Either way, base your decision of whether to go to the healthcare provider or not on how you feel. 2 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Kramer LD. Overview of Viruses. Merck Manual Professional Version. American Lung Association. Pneumonia Symptoms and Diagnosis. Additional Reading Andre M, Gröndal H, Strandberg E-L, Brorsson A, Hedin K.Uncertainty in clinical practice – an interview study with Swedish GPs on patients with sore throat.BMC Family Practice. 2016;17:56.doi:10.1186/s12875-016-0452-9. Shapiro, D., Lindgren, C., Neuman, M., & Fine, A. (2017).Viral Features and Testing for Streptococcal Pharyngitis.Pediatrics,139(5), e20163403. doi:10.1542/peds.2016-3403 Steed AL, Stappenbeck T.Role of Viruses and Bacteria-Virus Interactions In Autoimmunity.Current opinion in immunology. 2014;0:102-107.doi:10.1016/j.coi.2014.10.006. By Rod Brouhard, EMT-P Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit