Health Topic

Flu, Pneumonia, COVID-19, and the Common Cold

We’ve all experienced being sick – whether it was the flu, a cold or something more serious like pneumonia, or even COVID-19. All are unpleasant, and without a diagnosis from a doctor, sometimes very hard to differentiate from one another. There are ways we can help prevent ourselves, and others, from getting sick.

Friends wearing face coverings tap elbows to greet each other outside.

Understanding the Basic Facts

Knowing the causes and symptoms of the flu, pneumonia, COVID-19, and the common cold is your first step to avoiding them. This is meant to be a guide and not used as a self-diagnosis tool. When in doubt, please check with your doctor.

Influenza (Flu)

The flu is the common term for an infection caused by influenza viruses A and B. It most often occurs during the late fall and winter, but you can get it at any time. It’s not the same as the common cold. It comes on suddenly and its symptoms are more severe and last longer than a common cold. If you are older or have asthma, emphysema, heart disease, kidney disease or diabetes you are more likely to get the flu.

Symptoms of the flu include a dry cough, severe muscle aches, fever, and fatigue. It can also cause headaches. The flu does not usually cause vomiting or diarrhea in adults.


Pneumonia is a lung infection caused by breathing in viral or bacterial germs. If you have asthma, emphysema, heart disease, cancer, or diabetes you are more likely to get pneumonia. People who smoke are also at a higher risk for developing it. Pneumonia is more common during the winter months but can also occur throughout the year.

When you have pneumonia, you may have a cough with phlegm, get a fever, and have shortness of breath. You can also have chest pain when coughing or breathing deeply.


SARS-CoV2 is a type of coronavirus. The disease that it causes is called COVID-19. COVID-19 can occur all year long. Those with an increased risk of serious complications are those who are unvaccinated, are older, or have heart disease, lung disease, or diabetes.

Most people experience a dry cough, aches, fever, and fatigue. COVID-19 patients can also lose their sense of taste and smell. About 10% of COVID-19 patients can get diarrhea as their first symptom, even before a fever and cough. We are still learning new information about this infection.

Common Cold

The common cold is an infection caused by a virus called rhinovirus — “rhino” is the Greek word for nose. Common colds give us a runny nose and make us sneeze. Symptoms are generally fairly mild and last less than two weeks.

When to Seek Treatment

Your symptoms can vary depending on your age and health condition. If you are experiencing any combination of the following symptoms, call your doctor and schedule an appointment right away:

  • Fever (temperature more than 100 degrees F)
  • Extreme tiredness
  • Body aches
  • Headache
  • Cough
  • Sore throat
  • Runny nose
  • Difficulty breathing
  • Pain when taking deep breaths
  • Shaking, chills, and increased heartbeat

Testing for Infection

When you visit a doctor with the symptoms above, they will probably test you for both the flu and COVID-19. Pneumonia examinations are a bit different. You might receive a physical exam and a chest X-ray. Many COVID-19 patients will receive a chest X-ray too and in some cases, your doctor might order a CAT scan. Other tests like blood work, may be given if symptoms are bad or if you have other health problems.

Ways to Avoid Getting Sick

The best way to avoid getting sick is to not get exposed. To prevent infection, and to not spread viruses, follow these easy steps:

  • Wash your hands regularly for at least 20 seconds. That’s about as long as singing the happy birthday song twice.
  • Wear a face covering, preferably an N95 or similar mask if available, and practice social distancing when in public. If you can, try to stay away from sick people and people that don’t live in your home.
  • Use hand sanitizer.
  • Cough or sneeze into a tissue or the inside of your elbow.

Flu, Covid-19, and Pneumonia Vaccination Checklist

While not 100% effective, vaccinations can help prevent serious illness for those who become infected. They also help prevent the spread to other people. If you do get sick, you may get other health conditions that could require doctor’s appointments or time in the hospital. Being ill could also prevent you from being able to spend time with friends and family.

  • Flu: It’s important that you get your annual flu shot which is usually available early fall each year.
  • Pneumonia: There are 4 types of pneumonia vaccines. Depending on your vaccination status, you may need 1 or 2 pneumonia vaccines after the age of 65 that should last the rest of your life.
  • COVID-19: Current information about the different vaccines can be found here. It has been shown that the COVID-19 vaccines currently available in the United States are highly effective at preventing COVID-19. Your doctor can help clarify how often they should be given based on which one you receive. It is incredibly important that everyone who is eligible get vaccinated or boosted.

Frequently Asked Questions

Do vaccines cause the flu or COVID-19?

No. Some people may have side effects, such as headache, fever, nausea or aches, but these will usually pass within a few days and are less severe than the actual flu or COVID-19.

Do I need the flu vaccine or COVID-19 vaccine if I’m healthy?

Yes. By being vaccinated, healthy people can help prevent the spread of viruses to those who are more likely to get sick.

Do I still need to get vaccinated if I already had the flu or COVID-19?

Yes. Prior infection doesn’t offer 100% protection. Flu shots are good for one year, and the CDC sometimes recommends a second shot. People who had COVID-19 plus the vaccine have more antibodies than those who didn’t get the virus.

Do I need a flu shot every year?

Yes. The virus changes, so the vaccine is adjusted yearly. A flu shot helps protect against the strain of virus expected that year.

Can I get the flu or COVID-19 if I’m vaccinated?

Yes. Vaccines are not 100% effective. If you get sick after getting vaccinated, your symptoms will likely be less severe. Vaccines also reduce your risk of spreading viruses.

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Flu, Pneumonia, COVID-19, and the Common Cold Knowledge Check

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