Is it RSV, a cold, the flu or COVID? What to know about the differences between illnesses

All 4 are respiratory infections caused by viruses

The flu, a cold, COVID and RSV are all respiratory infections caused by viruses.

While many of their symptoms overlap, there are often differences in the severity of illness.

SymptomsRSVColdFluCOVID
Runny noseXXXX
Decrease in appetiteX
CoughingXXXX
SneezingXX
FeverXRareXX
WheezingX
Stuffy noseXXX
Sore throatXX
Post-nasal dripX
Watery eyesX
HeadachesXX
FatigueXX
Muscle achesXX
Vomiting/DiarrheaSometimesX
Shortness of breathX
Loss of taste or smellX

What is RSV?

Respiratory syncytial virus (RSV) is a common respiratory virus that usually causes mild, cold-like symptoms. While most people recover in a week or two, it can be a serious illness for infants and older adults.

RSV is the most common cause of bronchiolitis and pneumonia in children younger than one in the United States.

People infected with RSV usually show symptoms within 4 to 6 days after getting infected. Symptoms appear in stages, not all at once. In very young infants, some of the only symptoms might be irritability, decreased activity and breathing difficulties.

Symptoms usually include the following, according to the CDC:

  • Runny nose
  • Decrease in appetite
  • Coughing
  • Sneezing
  • Fever
  • Wheezing

The only current way to treat RSV is through pain management and drinking enough fluids. Make sure to speak to your healthcare provider before giving children nonprescription cold medicines.

Click here to learn more about RSV.

Read: 6-year-old boy dies from complications of RSV in Oakland County

What is the difference between a cold and flu?

While they are both contagious respiratory illnesses, they are caused by different viruses, according to the CDC.

Flu is caused by influenza viruses only. The common cold can be caused by a number of different viruses, including rhinoviruses, parainfluenza, and seasonal coronaviruses (not the same thing as the virus that causes COVID-19).

Flu and the common cold have similar symptoms, which can make it difficult to tell the difference between them based on symptoms alone. Generally, flu is worse than a cold and symptoms are more intense and begin more abruptly.

The symptoms of flu can include fever or feeling feverish/chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, and fatigue (tiredness).

Cold symptoms are usually milder than the symptoms of flu. People with colds are more likely to have a runny or stuffy nose. Colds usually do not result in serious health problems.

Cold vs Flu graphic from the CDC. (CDC)

Read: Michigan’s chief medical executive discusses all things flu, RSV, common cold, and COVID-19

Similarities and differences between flu and COVID-19

While they are both contagious respiratory illnesses, they are caused by different viruses.

COVID-19 is caused by infection with a coronavirus (SARS-CoV-2) first identified in 2019. Flu is caused by infection with a flu virus.

They can share the following symptoms, according to the CDC:

  • Fever or feeling feverish/having chills
  • Cough
  • Shortness of breath or difficulty breathing
  • Fatigue (tiredness)
  • Sore throat
  • Runny or stuffy nose
  • Muscle pain or body aches
  • Headache
  • Vomiting
  • Diarrhea (more frequent in children with flu, but can occur in any age with COVID-19)
  • Change in or loss of taste or smell, although this is more frequent with COVID-19.

How long do symptoms appear after exposure? Someone with the flu will usually experience symptoms anywhere from one to four days after infection. Someone with COVID will experience symptoms anywhere from two to five days and up to 14 days after infection.

How long can someone spread the virus? Someone with the flu is potentially contagious for about one day before they show symptoms. Older children and adults appear to be most contagious during the first 3 to 4 days of their illness. Someone with COVID can begin spreading the virus two to three days before their symptoms begin. They can also spread the virus without experiencing any symptoms.

Covid and flu can result in the following complications, according to the CDC:

  • Pneumonia
  • Respiratory failure
  • Acute respiratory distress syndrome (fluid in the lungs)
  • Sepsis (a life-threatening illness caused by the body’s extreme response to an infection)
  • Cardiac injury (for example, heart attacks and stroke)
  • Multiple-organ failure (respiratory failure, kidney failure, shock)
  • Worsening of chronic medical conditions (involving the lungs, heart, or nervous system or diabetes)
  • Inflammation of the heart, brain, or muscle tissues
  • Secondary infections (bacterial or fungal infections that can occur in people with flu or COVID-19)

Click here to learn more about the similarities and differences between the flu and COVID.

Read: More health coverage

Cold and flu season is here, but there are plenty things that you can do to survive a virus.

About the Author:

Kayla is a Web Producer for ClickOnDetroit. Before she joined the team in 2018 she worked at WILX in Lansing as a digital producer.