How Your Body Fights Off Cold and Flu

Colds and flu are among the most common human ailments; adults suffer two or three colds per year on average,¹ while children can get two to nine colds per year.^2,3,4 Luckily, your body naturally has ways to fight off normal flu symptoms and cold viruses—and get you back to health.

The Immunity Challenge

A cold is an infection of the upper respiratory system caused by one of about 200 viruses.^1,5 The flu is also an upper respiratory illness caused by one of several specific flu viruses.⁶ Given all these different sources, it’s no wonder we don’t have a cure for the common cold—or flu. Instead, it’s up to your immune system to help fight back.

How a Virus “Thinks”

The immune system is designed to monitor, recognize, and even remember the virus and take action to eliminate it, when a virus invades healthy cells. The immune system does this by releasing chemicals that trigger virus-fighting cells—which are then sent to wipe out the enemy.⁷

How Your Body Fights Back Against Flu and Cold Viruses

While the immune system is hard at work fighting off offending viruses, the body experiences infections in different ways. Many symptoms of cold and flu are the result of the immune system trying to fight the infection.⁵ For example, chemicals released by the body’s cells may elevate body temperature, i.e., you get a fever – one of the normal flu symptoms.⁸

Making Sense of Your Symptoms

Cold and normal flu symptoms aren’t just annoyances that can often keep you on the couch all day. They actually indicate what your immune system is doing to fight off the infection.

Runny Nose/Nasal Congestion—A runny nose helps wash germs from the nose and sinuses.⁹

Coughing and Sneezing—Within a few days of a viral infection, the fluid from a runny nose may change color from clear to yellow to green.⁴ Mucus is designed to trap offending viruses, which are efficiently and quickly expelled from the body through coughing and sneezing.⁸

Fever—Fevers fight influenza viruses. Because viruses are sensitive to temperature changes and cannot survive above normal body heat, your body uses fever to help destroy them.⁸

Muscle Aches and Pain—The muscle soreness you may experience with the flu is also a product of your body’s immune response. The immune system pulls protein from muscles, leaving your muscles achy.⁵

Finding Relief

When you need cold or flu symptom relief, use Vicks® products to treat and relieve your specific symptoms to help you feel better. Your doctor or pharmacist can help you find the medicine that is appropriate for you. Be sure to read each label and use each product as directed.

Staying Positive

Keep smiling, even when you’re feeling down. Researchers have found that a positive attitude with a general attitude of vigor is associated with less severe symptoms.¹

Turner, R.B. The common cold. In: Mandell, G.L., Bennett, J.E., Dolin, R., eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2009: Chap 53.
National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID). Common Cold. Available at: https://www.cdc.gov/dotw/common-cold/index.html. Accessed 11 Jan 2012.
Centers for Disease Control and Prevention (CDC). Publication “Rhinitis vs Sinusitis in Children” 2009. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7173501/. Accessed 12 January 2012.
National Institutes of Health (NIH). Common Cold. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000678.htm. Accessed 27 May 2010.
Eccles, R. Understanding the symptoms of the common cold and influenza. Lancet Infect Dis. 2005 Nov;5(11):718-725. Available at: http://www.ncbi.nlm.nih.gov/pubmed/16253889.
National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIAID). Flu (Influeza). Available at: http://www.niaid.nih.gov/TOPICS/FLU/UNDERSTANDINGFLU/Pages/definitionsOverview.aspx. Accessed 12 Nov 2011.
U.S. Department of Health and Human Services. National Institutes of Health. National Institute of Allergy and Infectious Diseases. NIAID Science Education. Understanding the Immune System: How It Works. NIH Publication No. 07-5423. September 2007:1, 25. Available at: http://www.niaid.nih.gov/topics/immuneSystem/Documents/theimmunesystem.pdf. Accessed 11 Nov 2011.
U.S. Department of Health and Human Services. National Institutes of Health. National Institute of Allergy and Infectious Diseases. NIAID Science Education. Understanding Microbes in Sickness and in Health. NIH Publication No. 09-4914. September 2009.Available at: http://www.niaid.nih.gov/topics/microbes/Documents/microbesbook.pdf. Accessed 14 Nov 2011.
Centers for Disease Control and Prevention (CDC). Publication “Common Cold and Runny Nose.” Available at: http://www.cdc.gov/getsmart/antibiotic-use/URI/colds.html. Accessed 14 Nov 2011.