Get $15 off your first month of ED treatment (if prescribed). Start now.

Health Guide delivered to your inbox

You can unsubscribe at any time.
Please review our privacy policy for more info.

Last updated September 13, 2021. 7 minute read

COVID-19 vs. the flu vs. the common cold

COVID-19 is a respiratory disease that can have symptoms similar to the flu and the common cold. Here’s the difference.

Dr Chimene Richa Md Written by Chimene Richa, MD
Reviewed by Tzvi Doron, DO

What is COVID-19?

Coronavirus disease 2019 (COVID-19) is a respiratory disease caused by a new coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was first reported in late 2019 in Wuhan, Hubei Province, China, and quickly spread to the rest of the world. According to the Centers for Disease Control and Prevention (CDC), SARS-CoV-2 is spread by virus-infected respiratory droplets that are produced when an infected person coughs or sneezes—these droplets can then travel up to six feet (CDC, 2021). While less likely, it is possible that the virus can spread by touching a surface that has SARS-CoV-2 on it and then touching your mouth, nose, or eyes. 

Coronaviruses belong to a family of viruses that cause different illnesses. Some cause a mild illness like the common cold while others cause more severe conditions, like Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS). COVID-19 is genetically similar to SARS but is not as deadly. COVID-19 can cause mild to severe symptoms—more than 80% of people with COVID-19 have mild disease. About one in six people have more severe symptoms (WHO, 2020).

The signs and symptoms of COVID-19 usually appear within 10 days of the time of infection and can include fever, dry cough, tiredness, aches and pains, sore throat, diarrhea, eye inflammation, headache, loss of taste, loss of smell, discoloration of fingers or toes, difficulty breathing, shortness of breath, chest pain or pressure (WHO, 2020). In rare instances, the incubation period (period after infection before symptoms occur) can be over 20 days.

There is no cure available for COVID-19 at this time. In October of 2020, the Food and Drug Administration (FDA) approved the first treatment for COVID-19: an antiviral drug called remdesivir. In one study, remdesivir was shown to improve symptoms, and shorten hospital stays in patients hospitalized for COVID-19 infections (Beigel, 2020). This treatment is not intended for everyone who contracts COVID-19. Vaccines are now widely available in the United States and are our best bet for getting back to normal. Getting vaccinated reduces the risk of catching coronavirus and reduces the chance that you will get a serious case if you do come down with the virus. Contact your local pharmacy to find out how you can get vaccinated.

Vitals

  • COVID-19 is the disease caused by the novel coronavirus that was first reported in Wuhan, Hubei Province, China in 2019. Influenza (the flu) has been around for much longer, and affects approximately 8% of the population in the U.S. and one billion people worldwide each year. The common cold affects millions of people every year. Most adults get 2–3 colds per year, and children often get more. COVID-19, the flu, and the common cold are all similar in terms of common symptoms, prevention, and method of spread. They differ in terms of infection rates, complications, and fatality rates.

What is the flu?

Influenza, commonly known as “the flu,” is caused by several different strains and types of human influenza viruses. The two main types of seasonal flu viruses are influenza A and influenza B. Flu season typically starts in September or October, peaks between December and February, and then ends around April or May (CDC, 2020). Flu viruses can cause mild to severe symptoms, with death occurring in the most serious cases. The World Health Organization (WHO) estimates that about one billion people get the flu yearly worldwide (WHO, n.d.) During the 2019–2020 flu season alone, there have been as many as 56 million people suffering from the flu, with up to 62,000 deaths from the disease in the US (CDC, 2020a). The CDC estimates that about 8% of the population in the U.S. catches the flu each year. 

The flu is spread from person to person by virus-infected respiratory droplets that are produced when an infected person coughs or sneezes. Less often, you could possibly get the flu by touching an object that has flu virus on it and then touching your mouth, nose, or eyes. According to the CDC, people who have the flu are the most contagious during the first 3–4 days after they start having symptoms (CDC, 2020a). However, it is possible for healthy-appearing infected people who have not developed symptoms yet to pass the flu virus on to others; they may not even realize that they are sick. The signs and symptoms of the flu include fever/chills, cough, sore throat, body aches, runny/stuffy nose, and feeling tired. Flu symptoms usually begin about two days after you contract the virus (CDC, 2020b).

Most people recover from the flu without any complications, but some people can develop serious illnesses, like pneumonia, ear infections, sinus infections, as well as worsening of other health problems like asthma or diabetes. In some cases, hospitalization or even death can occur (CDC, 2020b). Those with the highest risk of developing serious complications from the flu include adults aged 65 and older, children younger than five years old, people with medical problems like asthma, and pregnant women. 

If you do get the flu, antiviral medications (if taken within two days of getting sick) can help improve your symptoms and lessen the time you are sick by one or two days. However, prevention is still important. The most important way to prevent yourself from getting the flu in the first place is to get the flu vaccine each year. While not a guarantee that you won’t get the flu, the flu vaccine reduces flu-related symptoms and decreases your risk of having a serious complication from the flu. Other things you can do to keep from catching the flu include frequent hand-washing, avoiding people who are sick and staying home if you develop symptoms.

What is the “common cold”?

Millions of people in the U.S. get the common cold—adults have around 2–3 colds every year, and children may have even more (CDC, 2019). It is a major cause of missed work or school. More than 200 viruses cause the common cold, including strains of coronavirus, adenovirus, respiratory syncytial virus, and enterovirus, but rhinovirus is the number one cause of the common cold (CDC, 2019). Like other respiratory illnesses, the common cold is spread through close personal contact and airborne respiratory droplets. The most common symptoms are cough, runny nose, sore throat, headaches, and body aches. While most people get better within 7–10 days, those with weak immune systems or lung conditions may develop a more serious illness, like pneumonia (CDC, 2019).  

There is no cure for the common cold, and therapies focus on improving your symptoms. Prevention involves healthy practices like frequent hand-washing, avoiding people who are sick, and staying home if you develop symptoms.

COVID-19 vs. the flu vs. the common cold: Putting it all together

There are both similarities and differences between COVID-19, the flu, and the common cold, and it can be difficult to tell them apart. These figures summarize how these three respiratory viruses compare to each other.

What do COVID-19, flu, and common cold viruses have in common?

How the virus spreads By virus-infected respiratory droplets that are produced when an infected person coughs or sneezes; may also get it by touching contaminated surfaces
Symptoms Fever, cough, runny/stuffy nose, sore throat, headaches, body aches, and feeling tired
Prevention Frequent hand washing, staying home if you have symptoms, and limiting contact with people who are sick
Treatment Mainly focuses on improving symptoms; in severe cases, may require hospitalization

How are COVID-19, flu, and common cold viruses different?

COVID-19 Flu Common cold
Cause SARS-CoV-2 virus Different types and strains of influenza virus; mainly influenza A & influenza B viruses Rhinovirus is the most common cause; also caused by strains of coronavirus, adenovirus, and enterovirus
Number of infections Continuing to increase Worldwide: Hundreds of millions
Millions of people get the common cold, with adults usually getting 2–3 colds per year
Timing of symptoms Symptoms typically appear within 10 days of exposure Symptoms can start from 1–4 days after exposure Start gradually and usually peak 3–4 days after illness starts
When contagious May be contagious before symptoms start May be contagious 1 day before symptoms start and up to 5–7 days after getting sick May be contagious for a few days before symptoms start and until all symptoms resolved
Risk of infection (in the US) Increased risk if you have recently been in close contact with someone who has COVID-19. Increased risk age >65 and underlying medical conditions Children 0–17 years: 3% 
Adults 18–64 years: 8.8%
Adults 65 and up: 3.9%
Adults get 2–3 colds per year (on average) and children may get more
Antiviral medication Remdesivir Oseltamivir
Zanamivir
Peramivir
Baloxavir marboxil
None
Vaccines mRNA and viral vector vaccines available Yes—need to get it every year None
Complication rate Varies depending on age and other risk factors Worldwide: 3–5 million serious cases
US: 410,000–740,000 hospitalizations per year due to flu

Risk of serious illness increased in adults  65 years and older, people with medical problems (asthma, diabetes, or heart disease), pregnant women, and children younger than 5
Lower risk than flu
Number of deaths Continuing to increase Worldwide: 290,000–650,000 per year
US: 24,000–62,0000 per year
Very unlikely

Conclusion

This year, in addition to worrying about the cold and flu, there is a new player in the game—COVID-19. It is not always easy to know if your cough and sniffles are from the cold, the flu, or COVID-19. The best thing you can do for yourself and your loved ones is to get vaccinated. Vaccination reduces the risk of contracting coronavirus, protecting you and the people around you. In addition, it’s important to use healthy hygiene practices, like frequent hand-washing, avoiding people who are sick, and staying home if you develop symptoms. Encourage friends and family members to do the same. Talk to your healthcare provider if you have any questions or concerns about your symptoms or if your symptoms are severe. 

References

  1. Beigel JH; et. al. (2020, October 8). Remdesivir for the Treatment of Covid-19 – Final Report. New England Journal of Medicine. Retrieved from https://pubmed.ncbi.nlm.nih.gov/32445440/

    Centers for Disease Control and Prevention (CDC) – Common Cold. (18 March 2019). Retrieved September 13, 2021, from https://www.cdc.gov/dotw/common-cold/
  2. Centers for Disease Control and Prevention (CDC) – Coronavirus Disease 2019 (COVID-19). (13 September 2021). Retrieved September 13, 2021, from https://www.cdc.gov/coronavirus/2019-ncov/faq.html#basics
  3. Centers for Disease Control and Prevention (CDC)- Prevent Getting Sick, (27 April 2021). Retrieved September 13, 2021, from https://www.cdc.gov/coronavirus/2019-ncov/community/get-your-household-ready-for-COVID-19.html
  4. Centers for Disease Control and Prevention (CDC) – Preliminary In-Season 2019-2020 Flu Burden Estimates. (28 February 2020a). September 13, 2021, from https://www.cdc.gov/flu/about/burden/preliminary-in-season-estimates.htm
  5. Centers for Disease Control and Prevention (CDC) – Seasonal Influenza (flu). (28 February 2020). Retrieved September 13, 2021, from https://www.cdc.gov/flu/index.htm
  6. World Health Organization (WHO) – Coronavirus. (2020). Retrieved September 13, 2021, from https://www.who.int/health-topics/coronavirus
  7. World Health Organization (WHO) – Influenza: Are we ready? (n.d) Retrieved September 13, 2021 from https://www.who.int/influenza/spotlight
  8. Worldometer: COVID-19 Coronavirus Outbreak (2021) Retrieved September 13, 2021 from https://www.worldometers.info/coronavirus/#countries