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COVID-19 vs Flu Symptoms

Written by Ada’s Medical Knowledge Team

Updated on

Overview:

  • COVID-19 and flu can cause similar symptoms, making distinguishing between the two conditions challenging.
  • Both conditions can cause severe symptoms and complications in some people.
  • COVID-19 is more contagious than influenza.
  • The symptoms of COVID-19 generally last longer than those of influenza

COVID-19 vs flu: in order to stop the spread of the coronavirus, it’s essential to understand the characteristics of COVID-19 and the similarities that the condition has to other respiratory illnesses such as the flu. This article will discuss the differences and similarities between COVID-19 and the flu. 

What is the difference between influenza (flu) and COVID-19?

Both influenza and COVID-19 are respiratory illnesses that are highly contagious. They’re both caused by viruses, which can be spread from one person to another when an infected person sneezes, talks, or coughs. COVID-19 is caused by the coronavirus, whereas flu is caused by an influenza virus. Both can cause severe symptoms, although COVID-19 is more likely to cause severe illness in some people. The viruses related to both of these conditions can mutate and evolve, which can bring along slight changes in the symptoms you may experience. 1

COVID-19 symptoms vs the flu

COVID-19 and the flu can cause a variety of symptoms that are quite similar. The intensity of the symptoms can also vary greatly, ranging from no symptoms to mild discomfort and even severe symptoms, especially for those with underlying risk factors. The following chart can give you an insight into the symptoms of COVID-19 vs. the flu. 1 2 3

Symptom

COVID-19

Flu

Fever

Common

Common

Headache

Common

Common

Body aches

Common

Common

Fatigue

Common

Common

Stuffy, runny nose

Common

Sometimes

Chest pain

Common

Sometimes

Trouble breathing

Common

Common

Shortness of breath

Common

Rare

Loss of taste or smell

Common

Sometimes

Coughing

Common

Common

Sore throat

Common

Sometimes

Loss of appetite, vomiting

Sometimes

Common

Diarrhea

Sometimes

Common

Sneezing

Rare

Rare

Although both COVID-19 and the flu cause mild to moderate symptoms in most cases, they can also lead to severe illness, possibly resulting in hospitalization or death. There are a few groups of people who are considered to be at a higher risk of serious complications due to these conditions: 1

  • The senior
  • People with chronic medical conditions such as asthma, diabetes, or heart disease
  • Pregnant people 

Some possible complications of both the flu and COVID-19 are: 1

  • Pneumonia
  • Respiratory failure
  • Acute respiratory distress syndrome
  • Sepsis
  • Heart attack or stroke
  • Multiple-organ failure 
  • Worsening of already existing chronic medical conditions
  • Inflammation of the heart, brain, or muscle tissues
  • Secondary infections caused by bacteria or fungi

There are also a few complications which are only associated with COVID-19, being: 1

How can you tell the difference between flu and COVID-19?

Knowing whether your symptoms are caused by COVID-19 vs. the flu isn’t possible by evaluating the symptoms alone. This is because there’s a big overlap in symptoms between both conditions. Apart from that, other conditions, such as the common cold or allergies, can cause similar symptoms. This can be done using a PCR test or an antigen test. Both require a swab from the back of the throat or the nose, which can then be analyzed. 4

How long does influenza last in comparison to COVID-19?

The period you’re experiencing symptoms can vary in COVID-19 vs. The flu can cause symptoms that typically improve for most people within 3 to 7 days In some cases, some symptoms such as cough and a general unwell feeling may stay present for over 2 weeks. People at risk may also experience complications that extend the unwell period. 6

The symptoms of COVID-19 usually last longer, ranging from days to weeks. Most people fully recover within 12 weeks, although some people may experience symptoms for longer than that. This is called long COVID. 7

Which is more contagious: influenza or COVID-19?

COVID-19 and the flu are both highly contagious. In general, the coronavirus is more contagious than influenza viruses. How contagious the virus is also depends on which variant is circulating, as some variants, such as Omicron, transmit easier from one person to another. 8

People with the flu are generally contagious starting 1 day before their symptoms appear and during the first 3 - 4 days that they’re experiencing symptoms. Those who are infected with COVID-19 are usually contagious for a while longer. They can start spreading the coronavirus 2 - 3 days before their symptoms appear, and they stay contagious for about 8 days after the onset of their symptoms. 1

What is the difference in treatment between COVID-19 and the flu?

The immune system can clear both the flu and mild cases of COVID-19 and get better without additional treatment. However, you can alleviate your symptoms with home remedies. Some treatment methods work well for both conditions: 9

  • Taking plenty of rest 
  • Drinking enough water, which is especially important if you’re experiencing diarrhea or vomiting
  • Taking over-the-counter painkillers such as paracetamol, ibuprofen, and naproxen

There are certain antiviral drugs that your doctor may prescribe you. These antiviral drugs are different for the flu and COVID-19 and are usually provided if you are at risk for severe illness due to the infection

If you are eligible for antiviral treatment for COVID-19, you can get a prescription from your doctor for antiviral medication that supports your immune system in fighting the virus. It’s important to note that this medication should be started as soon as possible to be effective. 

How can you protect yourself from COVID-19 and the flu?

As both the flu and COVID-19 are caused by viruses, most measures that can prevent the spread of COVID-19 also help prevent the spread of the viruses that can cause the flu. Some steps which you can take to prevent yourself from getting infected with these viruses are: 11

  • Washing your hands regularly and thoroughly with water and soap.
  • Avoid touching your face with unwashed hands.
  • Improving ventilation in indoor spaces.
  • Avoiding contact with people who are sick or who have symptoms.
  • Wearing a mask that fits well, covering both nose and mouth. Masks can set a barrier for the particles you breathe, cough, or sneeze out. The N95 masks provide higher protection as they fit closely on the face and filter out particles, including the coronavirus.
  • Keeping a safe distance from others.

In addition, you can protect yourself from the coronavirus and the flu by getting vaccinated and keeping your vaccination up-to-date with the recommended booster shots. 

Wrapping up

Flu vs. COVID-19: both conditions are caused by viruses that mainly target the respiratory system. Although both conditions have a lot of similarities in symptoms and treatment, there are also significant differences between COVID-19 and the flu. These differences mainly involve that COVID-19 is more contagious, lasts longer, and can cause several severe complications for people who are at risk. 

FAQs

Q: Can you have COVID-19 and the flu at the same time? 
A: It is possible to get infected by both viruses simultaneously.

Q: COVID-19 vs flu: which is worse? 
A: It’s more likely to get severe complications with COVID-19. Apart from that, the symptoms of COVID-19 usually last longer as well.

Q: What are the differences between COVID-19 and flu symptoms? 
A: Although most of the symptoms of COVID-19 and the flu are quite similar, shortness of breath and a loss of taste or smell are usually more typical for people infected with the coronavirus. 

Q: How contagious is COVID-19 vs the flu?
A: COVID-19 is more contagious than the flu, especially the Omicron variant. It’s essential to keep health measures in mind to prevent the spread of the virus.