Key takeaways:
- COVID-19, respiratory syncytial virus (RSV), and the flu all cause similar symptoms like congestion and runny nose.
- COVID and the flu are more likely to cause fever, body aches, and headaches.
- Your symptoms can help point toward a diagnosis. But it’s impossible to tell which virus you have based on symptoms alone.
FG Trade/E+ via via Getty Images
During winter, it’s common to come down with a stuffy nose and sore throat.
Every year, viruses cause hundreds of millions of upper respiratory tract infections — also known as “colds.” These viruses are most active during the months that make up the cold and flu season.
With this year’s tripledemic, a cold could mean that you get COVID-19, the flu, or respiratory syncytial virus (RSV). These viruses can make you sicker than a regular cold virus. So what’s the difference between COVID, the flu, and RSV? And how can you tell which you’ve got?
Let’s take a look at how your symptoms can give you an important clue.
GoodRx Health
How are the flu, COVID, and RSV different from a regular cold?
A “cold” is a common term for a viral upper respiratory tract infection. Many viruses cause upper respiratory tract infections, including COVID, RSV, and the flu.
The special thing about COVID, RSV, and the flu is that they can also cause more serious lung illnesses and even affect other parts of the body.
Is there a way to tell if you have COVID, RSV, or the flu?
The only way to know for sure if you have COVID, RSV, or the flu is to get tested for COVID, RSV, and the flu.
But your symptoms can give you a clue about whether you have COVID, RSV, or the flu.
Flu symptoms tend to start all of a sudden, while COVID and RSV symptoms come on more gradually. They all cause similar symptoms, but certain symptoms tend to dominate with one illness over another. Fever, for example, is much more common with the flu and COVID than RSV.
Illness rates in your community can also give you an idea of which virus you’re more likely to have. If you’re sick and there’s a lot of flu in your area but not a lot of COVID or RSV, then you’re much more likely to be sick from the flu.
The CDC publishes weekly flu and COVID maps that can help you figure out if one virus is more active in your community. They also publish reports on local RSV activity.
Keep in mind that it’s possible to get two (or all three) of these viruses at the same time. In fact, having COVID and flu at the same time even has its own nickname — “flurona.”
What is COVID?
COVID-19 is a new type of coronavirus. Before 2019, coronaviruses were just common cold viruses — and not particularly aggressive ones. Now, COVID is one of the deadliest viruses in human history.
What are the most common COVID symptoms?
COVID symptoms keep changing as the virus creates new variants. Right now, the most common symptoms are:
- Cough
- Sore throat
- Fever
- Headache
- Body aches
- Runny nose and congestion
Symptoms can start gradually and get worse around day 2 or 3. COVID sore throat tends to be a very common symptom, especially at first.
Should you get tested?
It’s always a good idea to get a COVID test if you have cold symptoms.
COVID testing helps you figure out how long you need to isolate. It also helps you decide if you need to take extra precautions to protect any loved ones who are at higher risk of developing more serious COVID-related illness.
Another good reason to get tested is to find out if you should start antiviral treatment with Paxlovid. You need to start Paxlovid within 5 days of when you start feeling sick.
What COVID tests are available?
There are many COVID tests available, including home test kits that you can get at your local pharmacy without a prescription. Some tests give you results in minutes. There are also tests that take a few hours or even days to come back.
There’s a trade-off between time and accuracy. PCR tests take longer to come back but are more accurate. Antigen tests only take a few minutes but are less reliable.
For both types of tests, you need to provide a sample from inside your nose using a nasal swab. Some people wait too long to get their test and miss the window of opportunity to take Paxlovid.
What is RSV?
Respiratory syncytial virus (RSV) is known for causing bronchiolitis — a serious lower respiratory tract infection — in babies and young children. Adults can get RSV too, but most adults only develop colds. Older adults or those with chronic medical conditions may develop more serious illness.
What are the most common RSV symptoms?
RSV symptoms start off slowly. The most common symptoms are:
- Runny nose
- Stuffiness and congestion
- Cough
- Postnasal drip
Symptoms are at their worst on days 3 to 5, and then people start to gradually feel better. People with an RSV infection experience a huge surge in mucus production, which is why most symptoms are related to runny nose and congestion. Less common symptoms can include fever, body aches, and sore throat.
Should you get tested?
You probably don’t need a test for RSV, even if you have RSV-like symptoms. That’s because there’s no treatment for RSV.
If you live with someone who’s at higher risk for serious RSV illness — like an infant — knowing whether you have RSV may affect the precautions you decide to take in your home. You might decide to wear a mask or stay away from young children until you get better. But, even without getting an RSV test, you can easily take these steps if you’re sick.
What RSV tests are available?
Unlike COVID tests, there’s no rapid RSV tests that offer results within a few minutes. There are tests that can come back within a few hours. But these are only available from a healthcare provider’s office, urgent care center, or emergency room.
There is an at-home test by LabCorp that can test for COVID, RSV, and the flu with just one nasal swab. While you can do this test at home, you still have to drop off your sample at a local lab and wait for results, which take 1 to 2 days to come back.
On the bright side, the results of both at home and in office tests are very reliable.
What is the flu?
The flu is an illness caused by the influenza viruses. Influenza viruses come and go in a predictable pattern throughout the year.
What are the most common flu symptoms?
Unlike COVID and RSV, flu symptoms tend to start all of a sudden. People experience abrupt onset of:
- Fever
- Body aches
- Fatigue
- Headache
- Cough
- Congestion
- Sore throat
The symptoms tend to stay the same for 1 to 5 days before slowly fading over the next 3 to 5 days.
Should you get tested?
You might need a flu test if you have flu symptoms. There are antiviral treatments for the flu — like Tamiflu (oseltamivir) — which may help you feel better faster. But Tamiflu can also cause side effects, and some people opt to skip treatment.
Tamiflu and other flu antivirals work best if you start taking them within 48 hours of getting sick. So you don’t have a lot of time to decide whether to get a flu test. If you want to take antivirals, get a flu test as soon as possible. If you’re at higher risk of serious flu illness, get a flu test as soon as you develop symptoms.
Whether or not you test, remember the flu is contagious. Stay home from work or school until your fever goes away and you’re starting to feel better.
What flu tests are available?
There are rapid flu tests that can tell you within minutes whether you have the flu. Like COVID tests, these are antigen tests. That means you sometimes sacrifice accuracy for speed. Unlike COVID tests, rapid flu tests aren’t available over the counter. So you have to see a healthcare provider to get one done.
There are also PCR tests, which take longer to come back. But they’re more accurate. PCR tests are available at healthcare provider offices, urgent care centers, and emergency rooms.
There are also at-home PCR flu tests where you collect your own nasal swab and then drop off the sample at a lab. These are available as flu-only tests, flu-COVID combo tests, and now flu-COVID-RSV tests. While this saves you a trip to a provider’s office, you still have to wait 1 to 2 days to get your results.
The bottom line
COVID, the flu, and RSV are viruses that cause upper respiratory tract infections — better known as the common cold. But these viruses can also cause more serious illnesses like pneumonia. It’s impossible to know which virus is making you sick without a COVID, flu, or RSV test. That’s because all three cause similar symptoms.
There are antiviral medications for COVID and the flu. If you’re at high risk for serious illness from these viruses or want to start antiviral medication, it’s a good idea to get tested as soon as possible. These medications work best if you start them as soon as you get sick.
Leave a Reply