MedDroidCOVID-19 vs Flu
COVID-19 vs flu: differences in symptoms, tests and treatment
Written & medically reviewed by Dr. Sanjay Anbu, MBBS · Last reviewed
Medically reviewedCOVID-19 and flu (influenza) are both respiratory viruses with very similar symptoms such as fever, cough, sore throat and body ache. You cannot reliably tell them apart by symptoms alone, so a test is needed. Both can be serious in older adults, pregnant women and people with long-term illnesses, and vaccines are available for both.
Side-by-side comparison
| Feature | COVID-19 | Flu |
|---|---|---|
| Cause | SARS-CoV-2 coronavirus | Influenza A or B virus (including H1N1, often called swine flu) |
| Typical symptoms | Fever, cough, sore throat, tiredness, body ache, headache; loss of smell or taste can occur | Sudden fever, body ache, chills, cough, sore throat, marked tiredness |
| Onset & timing | Usually 2 to 14 days after exposure (often about 3 to 5 days) | Usually 1 to 4 days after exposure; starts suddenly |
| Key tests | Rapid antigen test or RT-PCR | Influenza RT-PCR or rapid test; combined panels can test for both at once |
| Treatment approach | Rest, fluids, fever control; antiviral medicines for some high-risk people, decided by a doctor | Rest, fluids, fever control; antiviral medicines for high-risk or severe cases, decided by a doctor |
| Danger signs | Breathlessness, low oxygen reading, chest pain, confusion, bluish lips | Breathlessness, chest pain, confusion, persistent high fever, worsening of a long-term illness |
General patterns only. Symptoms overlap and vary from person to person. On a phone, scroll the table sideways to see both columns.
How doctors tell them apart
- Symptoms overlap so much that doctors rely on testing.
- Loss of smell or taste is more often linked with COVID-19, but not everyone gets it.
- Local outbreaks and contact with a confirmed case guide which test is done first.
- A pulse oximeter reading helps decide who needs closer care in either illness.
See a doctor urgently if
- Difficulty breathing or breathing very fast
- Oxygen reading on a pulse oximeter below about 94%, or as your doctor advised
- Chest pain or pressure
- Confusion, unusual drowsiness or bluish lips
- Fever lasting more than 3 days, or getting better then suddenly worse
In an emergency, call your local emergency number (in India: 108 or 112).
Frequently asked questions
Can I have COVID and flu at the same time?
Yes, co-infection can happen. Combined tests can check for both.
Do antibiotics help?
No. Both are viral. Antibiotics are used only if a bacterial complication such as pneumonia develops.
Who should be extra careful?
Adults over 60, pregnant women, young children and people with diabetes, heart, lung or kidney disease or weak immunity.
Should I get vaccinated?
Vaccines exist for both and reduce the risk of severe illness. Ask your doctor which ones are right for you.
Related pages
Conditions
Symptoms
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Not a diagnosis. This page gives general health information to help you talk to a doctor; it is not medical advice and does not replace an examination or tests. Do not start, stop or change any medicine without a qualified clinician. MedDroid is an AI medical assistant and can make mistakes. In an emergency, call your local emergency number (in India: 108 or 112).