AUTHOR DETAILS : Thirumani Swetha | Andhra University | M.Pharm (Pharmaceutics)
PUBLISHED ON : 11th October 2026
INTRODUCTION
A runny nose, cough, sore throat, and tiredness can make it hard to know what is making you feel sick. A common cold and the flu share many symptoms, but their onset and severity can provide useful clues. [1,2]
How a Cold Usually Feels ?
A common cold is an infection caused by a virus that mainly affects the nose and throat. Different respiratory viruses can cause a cold. [3] Cold symptoms usually develop gradually rather than appearing all at once. You may notice a runny or blocked nose, sneezing, sore throat, cough, or a mild headache. Some people also have mild body aches or a low-grade fever. Cold symptoms are often most noticeable in the nose and throat. Most people recover from a common cold without needing specific medical treatment. [3] If your cold symptoms are mild, get plenty of rest and drink enough fluids while your body recovers. You should also pay attention to whether your symptoms are improving or becoming worse. [3]
HOW FLU IS DIFFERENT ?
Flu is also an illness that affects the respiratory system, including the nose, throat, and lungs, but it is caused by influenza viruses. [1] One of the clearest differences is how quickly the illness begins. Flu symptoms often appear suddenly, sometimes making you feel much worse within a short time. Flu symptoms may include fever or a feeling of feverishness, chills, cough, sore throat, headache, muscle or body aches, and strong tiredness. A runny or blocked nose can occur too. Body aches and fatigue are often more pronounced with flu than with a common cold. [1] However, not everyone with flu has a fever. Symptoms can vary from person to person, so a person can have flu even without feeling feverish. [1]
HOW CAN YOU TELL THE DIFFERENCE ?
Three useful clues are the speed of onset, the predominant symptoms, and the overall severity of the illness.
A cold usually develops gradually and is more likely to cause sneezing, a runny or blocked nose, and a sore throat. Flu often starts suddenly and is more likely to cause fever, chills, body aches, headache, and pronounced fatigue. But there is plenty of overlap. A cold can cause a cough and body aches, while flu can cause a runny or blocked nose and sore throat. Because cold and flu symptoms can overlap, symptoms alone may not always distinguish one illness from the other. When confirmation is needed, appropriate testing can help identify influenza. [2]
WHAT CAN YOU DO TODAY ?
- If your symptoms are mild, get adequate rest and drink enough fluids.
- Limit close contact with others while you are unwell and follow good respiratory hygiene.
- Consider speaking with a healthcare professional when symptoms become severe, get worse, or when there is a greater concern about complications.
Seek Urgent Medical Care If You Develop
- Difficulty breathing or shortness of breath.
- Persistent chest pain or pressure.
- Severe weakness, confusion, or dizziness.
- Symptoms that improve and then become worse again.
These can be warning signs of a more serious illness. Seek medical care promptly if you experience these symptoms. [1]
KEY TAKEAWAYS
- Flu commonly causes more pronounced body aches and fatigue, but symptoms vary between people.
- Not every flu patient may have fever.
- Symptoms alone cannot always confirm whether you have a cold or flu.
- Seek medical advice if symptoms worsen and urgent care for serious warning signs.
CONCLUSION
Knowing the typical differences between a cold and flu can help you decide what to do next. Rest, stay hydrated, and monitor your symptoms. If you are unsure about your illness or feel increasingly unwell, contact a healthcare professional. Early assessment can be particularly important for people at higher risk of complications.
REFERENCES
1. Centers for Disease Control and Prevention. Signs and symptoms of flu [Internet]. Atlanta (GA): CDC; 2024 Aug 26 [cited 2026 Sep 2]. Available from: https://www.cdc.gov/flu/signs-symptoms/index.html
2. Centers for Disease Control and Prevention. Cold versus flu [Internet]. Atlanta (GA): CDC; 2024 Aug 8 [cited 2026 Sep 2]. Available from: https://www.cdc.gov/flu/about/coldflu.html
3. MedlinePlus. Colds and the flu: what to ask your doctor—adult [Internet]. Bethesda (MD): National Library of Medicine; 2025 [cited 2026 Sep 2]. Available from: https://medlineplus.gov/ency/patientinstructions/000249.htm
Reviewed & approved by the :
Clinoryx Academy Editorial Team
Varrun Shah
Editor , Clinoryx Academy
Khushi Pandya
Editor , Clinoryx Academy
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