MedDroidCommon Cold vs Flu
Common cold vs flu: differences in symptoms, tests and treatment
Written & medically reviewed by Dr. Sanjay Anbu, MBBS · Last reviewed
Medically reviewedA cold is a mild virus infection of the nose and throat that comes on slowly, while flu (influenza) usually starts suddenly with high fever, body ache and exhaustion. Most colds get better on their own within a week to ten days. Flu can lead to complications such as pneumonia, especially in high-risk people.
Side-by-side comparison
| Feature | Common cold | Flu |
|---|---|---|
| Cause | Many viruses, most often rhinovirus | Influenza A or B virus |
| Typical symptoms | Runny or blocked nose, sneezing, sore throat, mild cough; fever is mild or absent | High fever, chills, body ache, headache, dry cough, marked tiredness |
| Onset & timing | Gradual over a day or two; usually better in 7 to 10 days | Sudden, within hours; tiredness can last a couple of weeks |
| Key tests | Usually none needed | Usually diagnosed on symptoms; flu test for high-risk or severe cases |
| Treatment approach | Rest, fluids, steam, saline nasal drops; antibiotics do not help | Rest, fluids, fever control; antiviral medicine for some people, decided by a doctor |
| Danger signs | Rarely serious; ear or sinus infection can follow | Breathlessness, chest pain, confusion, pneumonia, worsening of asthma, diabetes or heart disease |
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
- Speed of onset: sudden means flu, gradual means cold.
- High fever and severe body ache point to flu.
- Sneezing and a runny nose are typical of a cold.
- Testing is usually needed only when the result will change treatment.
See a doctor urgently if
- Difficulty breathing or chest pain
- High fever lasting more than 3 days
- Confusion or extreme drowsiness
- Bluish lips or fast breathing in a child
- Symptoms that improve then suddenly get worse
In an emergency, call your local emergency number (in India: 108 or 112).
Frequently asked questions
Can a cold turn into flu?
No. They are caused by different viruses. But a cold can be followed by another infection such as sinusitis.
Do I need antibiotics for a cold?
No. Antibiotics do not kill viruses and can cause side effects and resistance.
Is there a flu vaccine in India?
Yes. A yearly flu vaccine is available and is especially useful for older adults, pregnant women and people with long-term illnesses. Ask your doctor.
How long am I contagious?
With both, you are most contagious in the first few days of symptoms. Rest at home, cover coughs and wash hands.
Related pages
Conditions
Symptoms
More guides
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).