December 7, 2022
Is it the flu, COVID-19, RSV, or just a cold?
With talk of a ‘tridemic’ of respiratory illnesses, it’s natural to worry if you wake up feeling sick. Learn about the symptoms to watch for.
Cold season is upon us, and with it, the all-too-familiar sneezes and sore throats.
But with flu season hitting hard and early, plus talk of a possible winter surge in COVID-19 cases, you might worry that the cold you feel coming on is something more.
Parents of infants and young children may also be concerned about RSV, or respiratory syncytial virus. Almost all children have had an RSV infection by the time they are 2, but this year, the virus has begun spreading early and is causing more severe illness than usual. Older adults and people with heart and lung disease or weak immune systems are also at risk for severe RSV.
The chart below lays out the most common symptoms of a cold, the flu, and COVID-19. Visit kp.org/rsv to learn about the symptoms of RSV.
Cold, flu, or COVID-19: Know the symptoms
Signs and symptoms* |
Cold |
Flu |
COVID-19 |
| Symptom onset | Gradual | Sudden | Gradual |
| Muscle and body aches | Slight | Common | Sometimes |
| Cough | Sometimes | Common | Common |
| Diarrhea | Rare | Sometimes | Sometimes |
| Fatigue, weakness | Sometimes | Common | Common |
| Fever over 100 degrees | Rare | Common | Common |
| Loss of taste or smell | Rare | Rare | Sometimes |
| Shortness of breath or difficulty breathing | Rare | Rare | Common |
| Runny or stuffy nose | Common | Common | Common |
| Sneezing | Common | Sometimes | Sometimes |
| Sore throat | Common | Common | Common |
| Headache | Rare | Common | Common |
What to do if you feel sick
If you start to feel symptoms of a respiratory infection, taking a COVID-19 home antigen test is the quickest and easiest way to rule out a coronavirus infection and make sure you’re not putting others at risk. If your test result is positive, stay home and isolate, and contact your doctor if you need guidance or support. If your result is negative, retest 24 to 48 hours after your first test.
Most patients don’t need to be tested for flu or RSV unless there is a potential need for them to be hospitalized. But stay home if you feel sick to avoid spreading your illness to others.
For most healthy people, diseases such as the flu, COVID-19, and RSV will go away on their own. But if you need care or advice, we offer members several options, including completing an e-visit on kp.org/evisits, emailing your doctor, calling the advice number on your member ID card, or scheduling a video, phone, or in-person appointment.
If your child is having severe breathing problems or you see that their skin or fingernails have a bluish color due to a lack of oxygen, do not hesitate to go to an emergency department or call 911.
Learn more
Get advice on self-care, find out where to get vaccinated for COVID-19 and flu, and read about the symptoms of flu, COVID-19, and RSV.
