Sniffles, congestion, sneezing, and a cough are all classic signs of the common cold. Confusingly, they are also symptoms of another common and contagious respiratory infection called RSV (respiratory syncytial virus).
But there’s a key difference between the common cold and RSV: In certain vulnerable people, RSV can result in hospitalization and even death.
The very young and the old are among those at highest risk from RSV. Each year in the United States, hospitalizations due to RSV number 58,000 to 80,000 among children younger than 5 years old, and 60,000 to 160,000 among adults 65 and up, according to the Centers for Disease Control and Prevention (CDC).
Deaths related to RSV range from 6,000 to 10,000 among this older population, and from 100 to 300 among kids under age 5.
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Signs of Mild RSV and the Common Cold Often Overlap
Can you tell whether you have a cold or a mild case of RSV just by assessing how you feel? Not necessarily.
“They are both upper respiratory infections that have very similar symptoms that often start with runny nose, sore throat, and cough,” says Ana Weil, MD, assistant professor with the Center of Emerging and Re-Emerging Infections at the University of Washington’s department of medicine in Seattle. Both illnesses may cause a loss of appetite, sneezing, fever, and in children, irritability and decreased activity.
But a characteristic of RSV that separates it from a common cold is a runny nose with truly copious amounts of mucus, according to University of Utah Health.
Dr. Weil adds that compared with a common cold, RSV may affect the chest in children, who have small airways, as opposed to up in the nose and sinuses. The virus may lead to an overproduction of mucus in the lungs that can be very sticky and thick, according to the Respiratory Syncytial Virus Consortium in Europe.
Unlike a Bad Cold, Severe RSV Can Cause Rapid Breathing
The American Lung Association notes that a barking or wheezing cough can be one of the first signs of a more serious RSV illness, along with sharp, shallow, rapid breathing.
“With an infant, you may see that they’re breathing very fast and they’re panting, or you see that the area underneath the ribcage or at the base of the neck is getting sucked in with every breath,” says Afif El-Hasan, MD, a medical spokesperson for the American Lung Association and a pediatrician with the Southern California Medical Group in San Juan Capistrano. “We can see wheezing, fast breathing, and shortness of breath in other populations as well. In any case, it’s an emergency and you need to deal with that right away.”
In addition to this labored breathing, other indications of serious disease that warrant emergency attention include a high fever and a bluish color to the skin, particularly on the lips and in the nail beds, according to the American College of Emergency Physicians.
“Blue tinting, especially in and around the mouth, indicates you’re not oxygenating the blood like you should,” says Dr. El-Hasan.
Testing Is the Only Way to Know for Sure if It’s a Cold or RSV
The only sure way to diagnose RSV definitively is through a test, traditionally administered by a doctor or other healthcare provider.
“We have very sensitive, rapid diagnostic tests that make it easier to identify RSV early on,” says Dean Winslow, MD, an infectious-disease specialist and a professor of medicine at Stanford University in California.
Rapid tests, the most common type, involve taking a fluid sample from the nose. From the sample, the test can identify certain proteins from the RSV virus called antigens. Test results are usually available within an hour.
After receiving emergency use authorizations last year from the U.S. Food and Drug Administration, a company called LabCorp now offers an at-home collection kit for RSV, flu, and COVID-19 using a single swab. The swab sample goes back to LabCorp via expedited mail for analysis, with results usually returned within a day or two.
It Can Be Important to Know Whether You Have RSV and Not a Cold
Because RSV can lead to more serious outcomes than the common cold, diagnosing it early is important for people in high-risk groups.
“RSV can cause a particularly severe form of what’s called bronchiolitis, an infection or inflammation of the small airways, particularly in young children,” says Dr. Winslow. “It can actually even be fatal, particularly in premature children or even children born at term.”
He stresses that the virus can also cause bronchiolitis and other serious diseases, such as pneumonia, in older people (65 and up) and those with a weakened immune system or preexisting health condition, such as heart disease or chronic obstructive pulmonary disease (COPD).
RSV may also overtax the body and worsen some of these preexisting conditions, according to Weil. “It’s not that the virus directly affects the heart, for example, but fighting the virus places increased demands on the heart,” she says.
By diagnosing RSV early, those at high-risk of complications can be on the alert and in touch with their healthcare provider should their infection worsen.
With an early diagnosis, people with RSV can also take extra steps to prevent spreading the virus to those around them, particularly people in high-risk groups. Those precautions include avoiding close contact with others, covering sneezes and coughs, and washing hands often with soap and water.
The CDC says that people with RSV are usually contagious for three to eight days and may become contagious a day or two before they start showing signs of illness. Some infants and people with weakened immune systems can continue to spread the virus even after they stop showing symptoms, for as long as four weeks.
