Do You Have the Flu or COVID-19? How to Tell the Difference

COVID-19 and influenza share many overlapping symptoms, which is why they are frequently mistaken for each other. Common shared symptoms include:

• Fever: Both illnesses may cause fever, which can be high—especially with the flu

• Cough: Often dry with COVID-19; flu-related coughs may be dry or productive

• Fatigue: Severe tiredness and low energy are common and may linger after infection

• Body aches and headaches: Muscle and joint pain can occur with both

• Sore throat: Common early symptom in both illnesses

• Congestion or runny nose: More common with the flu, but also possible with COVID-19

• Shortness of breath: Can occur with both, but tends to be more pronounced with COVID-19

Although symptoms overlap, certain features can help differentiate the two:

• Onset of symptoms:

  • COVID-19 symptoms usually develop gradually over 2–14 days

  • Flu symptoms tend to appear suddenly within 1–4 days

• Unique symptoms:

  • COVID-19 is more likely to cause loss of taste or smell, diarrhea, shortness of breath, and prolonged fatigue

  • These symptoms are less common with the flu

Before testing, these questions may help guide your suspicion:

Did symptoms appear suddenly or gradually?
Flu symptoms often start abruptly and intensely, while COVID-19 symptoms typically build over several days.

Do you have a loss of taste or smell?
Sudden loss of taste or smell strongly suggests COVID-19 and is rare with the flu.

Have you been exposed to someone with COVID-19 or the flu?
Recent exposure can provide an important clue.

How long have symptoms lasted?
Flu symptoms usually resolve within 1–2 weeks. Symptoms that persist longer—especially fatigue or breathing issues—are more suggestive of COVID-19.

If you feel unwell, take the following steps to protect yourself and others:

1. Get Tested

Symptoms alone cannot reliably distinguish COVID-19 from the flu. Testing is the most accurate way to confirm your illness. Rapid tests are widely available. If symptoms persist despite a negative test, consider retesting or consulting a healthcare provider.

2. Isolate

While awaiting results—or if you test positive—stay home, avoid close contact, and wear a mask when around others. Remain home until your fever has resolved without medication.

3. Notify Close Contacts

Inform people you’ve been in close contact with so they can monitor symptoms and take precautions.

4. Manage Symptoms and Seek Care When Needed

Rest, hydration, and over-the-counter medications like acetaminophen or ibuprofen can help relieve mild symptoms. Providers can also help manage cough, congestion, and sore throat.

Seek emergency care immediately for:

• Difficulty breathing

• Chest pain

• Confusion

• Persistent high fever

5. Follow Up if Symptoms Persist

Ongoing fatigue, cough, or shortness of breath—especially after COVID-19—may require further evaluation.

Are there other illnesses that mimic COVID-19 or the flu?
Yes. The common cold and RSV (respiratory syncytial virus) can cause similar symptoms. Colds are usually milder, while RSV more often causes wheezing or severe breathing problems, particularly in infants and older adults.

Can you have COVID-19 and the flu at the same time?
Yes. Co-infection is possible, especially during flu season.

How can I protect myself?
Stay up to date on COVID-19 vaccines and boosters, receive your annual flu vaccine, wash hands frequently, avoid close contact with sick individuals, and consider masking in crowded indoor settings—especially if you are high-risk.

When you’re sick, staying home is often the safest choice. Call-On-Doc offers fast, reliable online care for both COVID-19 and flu treatment.

If appropriate, providers can prescribe antiviral medications such as:

• Paxlovid (nirmatrelvir) or Lagevrio (molnupiravir) for COVID-19

• Tamiflu (oseltamivir) for influenza

Prescriptions are available in as little as 15 minutes, with no appointments required.

Skip in-person visits and recover at home. Start your online consultation today.

Sources:

1. https://www.cdc.gov/flu/about/flu-vs-covid19.html
2. https://www.cdc.gov/covid/signs-symptoms/index.html
3. https://www.cdc.gov/flu/signs-symptoms/index.html