Is it a cold, flu, RSV or COVID-19? Here’s how to tell the difference
Christopher Connolly, MD, is a board-certified internal medicine physician at Inova 360º Concierge Medicine with more than 24 years of clinical experience. Dr. Connolly previously served as the Medical Director and Chief Medical Information Officer of Nova Medical Group and Urgent Care. Most recently, Dr. Connolly worked as a primary care physician for Inova Primary Care in Ashburn and as a lead physician informaticist for Inova Primary Care.
It might start as a sniffle or a headache. You know you’re coming down with something — but what? Is it just a cold? Or could it be RSV, the flu or COVID-19? Do you need to call your doctor or just hit the couch?
You can often tell these viruses apart — if you know what to look for. From there, you can determine when you need to seek medical care.
Different viruses, different symptoms
At first glance, colds, flu, RSV and COVID-19 can look alike. All of them can start with symptoms that feel like a “head cold.” But a closer look reveals that these illnesses have some key differences.
Common cold symptoms
The mildest of these viruses, the common cold usually doesn’t require a doctor’s visit. You probably have a cold if your symptoms come on slowly and get worse over a period of 1 to 3 days.
Common cold symptoms usually include:
- Cough, which can be dry or productive (coughing up phlegm)
- Fatigue (typically mild)
- Runny or stuffy nose
- Sneezing
- Sore or scratchy throat
- Watery eyes
A cold will usually not cause:
- Body aches
- Headache
- High fever
- Loss of taste or smell
- Wheezing
Signs of the flu
The flu tends to make people more miserable than a cold. One of the first signs that it’s not a cold is its sudden onset. Within hours, you go from feeling fine to feeling terrible. If you have the flu, your symptoms may include:
- Body and muscle aches
- Chills
- Dry cough
- Fatigue (often severe)
- Headache
- High fever up to 104 degrees Fahrenheit, which lasts up to 4 days
- Lack of appetite
- Vomiting or diarrhea (usually in children)
It’s less common for people with the flu to experience:
- Productive cough
- Stuffy or runny nose
- Wheezing or trouble breathing
Spotting symptoms of RSV
Respiratory syncytial virus (RSV) feels like a common cold to most young, healthy adults. But it’s not “just a cold.” Thousands of people — mostly adults over age 65 and infants — are hospitalized or die each year from RSV.
Symptoms of RSV often come on in stages and last a total of 7 to 14 days. Healthy adults may experience cold-like symptoms such as:
- Dry cough
- Headache
- Runny nose
- Sneezing
- Sore throat
Babies under 12 months of age and adults over age 65 may have more serious symptoms, including:
- Barking cough
- Cough with a lot of mucus
- Fever
- Irritability
- Loss of appetite
RSV can become severe and cause trouble breathing, which can be life-threatening. Seek emergency medical care if you notice:
- Blue lips or fingernails
- Nostrils flaring
- Rapid breathing
- Wheezing
COVID-19 symptoms
The current COVID-19 variant causes gradual, cold-like symptoms in most people. But like RSV, COVID-19 can be serious in older adults and people with other medical conditions.
The most common symptoms of COVID-19 include:
- Body and muscle aches
- Cough
- Diarrhea or vomiting
- Fatigue
- Fever and chills
- Headache
- Loss of taste or smell
- Runny or stuffy nose
- Sore throat
Loss of taste or smell is a telltale sign of COVID-19. This symptom is much less common with other illnesses.
When to recover at home
Most of the time, people recover from these infections on their own, but there are exceptions. RSV can be dangerous for infants and older adults. COVID-19 and flu are more serious for older adults and people with other health issues.
The best course of action with a mild virus is to stay home to avoid spreading the illness to others. If you don’t have other health conditions or a weakened immune system, you can:
- Drink plenty of water or other non-caffeinated, non-alcoholic beverages
- Rest as much as possible
- Take over-the-counter acetaminophen or ibuprofen to relieve symptoms
- Use nasal saline for a stuffy nose
If you’re concerned about any symptoms, don’t wait it out. Contact your primary care provider or head to an urgent care facility. Many medical offices offer telehealth visits so you can discuss your symptoms without leaving home.
When you need a test
Most medical offices can do rapid tests for COVID-19, the flu and RSV. Testing can be helpful because:
- It tells your provider what kind of treatment you may need. For example, some people may benefit from antiviral medication for COVID-19 or the flu.
- It helps you protect others. If you find out you have RSV and you plan to be around a baby, for example, you could reschedule your visit.
Consider testing if you:
- Are over age 65
- Have health conditions like diabetes, heart, lung or kidney disease, HIV or obesity
- Will have contact with someone at risk of severe illness, such as a baby, older adult or immunocompromised person
- Take immunosuppressant medications (medications that weaken the immune response)
- Work in a daycare or nursing home
When it’s an emergency
No matter what virus you have, some symptoms always require immediate medical treatment. Get emergency care if you or your loved one has:
- Bluish lips or fingernails
- Chest pain
- Dizziness
- Fever over 103 degrees Fahrenheit
- Sudden confusion
- Trouble breathing
- Wheezing
Stop illness before it starts
When it comes to any illness, prevention is critical. You can help reduce your risk of getting sick if you:
- Avoid being around people who are currently sick
- Get at least 7 hours of quality sleep each night
- Wash your hands regularly, especially after using the bathroom and before eating or preparing food
But even with the most diligent handwashing, you can still be exposed to viruses. Help protect yourself by getting vaccinated against:
- COVID-19: Vaccines protect against severe COVID-19 complications and lower your chances of getting long COVID. Vaccines are available for everyone 6 months and older, so talk with your provider to make sure you’re up-to-date.
- Flu: The flu vaccine reduces the risk of serious illnesses and hospitalizations and may reduce the length of symptoms. Everyone 6 months and older should get an updated flu shot yearly to protect against current flu viruses.
- RSV: The RSV vaccine is available to anyone who is pregnant or at least 60 years of age. Getting the vaccine during pregnancy helps protect your newborn from RSV. Talk with your provider about whether this vaccine could benefit you.
Inova can help with any illness Everyone gets sick sometimes. No matter what level of care you need, Inova is here for you. We offer many convenient primary care locations across northern Virginia and beyond. For urgent needs, our Go-Health Urgent Care provides same-day, walk-in and virtual care. Our expert Emergency Care
Very informative. Thank you.
Wonderful information.
6 months ago I (age 70) caught, perhaps, the common flu, it lasted almost two weeks. I made an appointment, but the appointment was a couple days after symptoms went away & I was deemed fine. Merely a couple days later I caught something more serious, perhaps RSV, lasting over two weeks, coughing up phlem (which I saved for analysis, but never got such done). During both bouts I tested negative for COVID. Anyway, I feel like getting the flu or RSV vaccine would be redundant – I wish I could be tested & learn which illnesses I’ve caught.
When I was a kid of 14, on Long Island, NY, I worked in a drug store delivering Rxs and stocking shelves. That was 1959. There was a large box of Sputum Cups in the upper level storage collecting dust. No one ever cam in to buy one. Too bad I didn’t save any when the Big Walgreens put the drug store out of business while I was still working there paying my way through college!
Great help in determining between illnesses
I wish I had been feeling well enough to look at this e-mail earlier. My husband and I are 76 years old and recently went through what we are pretty sure was RSV. Our son who lives with us got it in early Dec, from an unknown source. He isolated as much as possible in his room. I came down with it Dec 26, and my husband started symptoms 5 days later. My son is now better after a second short reoccurance. I am now about 50% recovered and getting my energy back. My husband who is disabled by Lewy Body Dimensia is starting to get better. He had more fever than our son or I did. One night my husband’s fever broke and his jamas and bedding were drenched. We all have had “foggy brains” throughout.
The thing we all noticed was how absolutely sticky (almost glue like) the mucus we had was–and I have not seen that noted elsewhere. My husband is still having jags of hard sneezing of 7-9 times, several times a day, enough to cause his eyes to get blood shot as well as fatigue him. This also populates his eyes with a white discharge that is very “burny” (but has been active for about 6 mo). Five eye doctors have assured us it is not infection. I am wondering if he has something else going on now and we should contact his doctor, or if these are within normal range of reactions? A wet wash cloth over his eyes for 5 minutes relieves the burning, but nothing seems to diminish the sneezing, which is continuing to increase in strength and frequency.
I have something very similiar going on here, on the tail end of three weeks of similar eye issues.
Did you figure out what it was?
Very helpful information as Ive caught the common cold from my husband today (watery burning eyes only) and we both got our spring Covid booster this past week so hoping for a quick recovery. Havent had a cold in years. Thanks
Very fatigue, scratching throat, my head feels big pressure (not headache). I’ve had covid 3 times. Last time, contracted 2 weeks from my doctors office. I went for my annual, started feeling sick 2 days later (on a Saturday). Monday got call from doctor’s office that 2 staff members had COVID the day I was there. And more infected on Friday….
I cannot get my energy up & never regained my lungs strength from first time covid in 2020. So since then always shortness of breath. Any one else feel like this after covid?
Yes I have times when I feel like I am not getting air to my lungs, A lot of times I have been bending over or walking for exercise. I was never this way before covid. I also lost my sense of smell and taste and have lost clumps of hair twice now. I had covid two years ago.
I started with an irritating cough non productive. My head felt like a bowling ball, post nasal drip constant with thick phlegm I just could not clear. I also had tiredness and just wanted to sleep. No desire for food or drink. I did also have some but not much sneezing. Struggling to get over this forcing myself to do at least one task before falling back into bed.
I came to check symptoms. Headache, productive cough, sneezing, low grade fever, fatigue, loss of taste (which could be caused by a stuffy nose – I hope) diarrhea, and sore throat. I felt lousy so I wanted to know what is going on. And now I’m worried. O_O
I recently retired 7/1/24 from 40+ yrs in healthcare with almost no sickness. Pneumonia out of the blue 03/2019, Flu 03/2020, COVID 01/2022, RSV 12/2023. I live alone so can minimize contact with others. Just got “respiratory something” 1 week ago after attending the county fair; all previous was after air travel. Based on symptoms, it doesn’t quite match any of the previous infections, but has characteristics of both COVID and RSV. Thicker/stickier than snot phlegm, went from throat into chest in 2 days. Now last 2 days loose stool and today fever on day 7! What is up with our respiratory stuff these days. Since COVID, I’ve had to use an inhaler due to wheeze, rales, crackle in lungs. Breathing is definitely different now. I’m going to be one of those people that wears a mask in the airport.
I have no idea what is going on. 1st bought severe chills stuffy nose foggy brain and horrible fatigue and body aches. Very congested and wheezing. Started to feel better about 4-5 days in and complete relapsed. Have had this sickness for 3 days and 3rd relapse today. The chills where so bad my body was shaking I just feel terrible.
This was very helpful & informative!! Thank you so much for helping to let us know to go to doctor OR take it easy!