How can you tell the difference between a common cold and the flu?

Reviewed by Yoshinori Abe, MD

Internal Medicine

Cold vs. Flu: What's the Difference?

The common cold typically causes mild symptoms, including a runny nose, sore throat, sneezing, and mild congestion. The flu (influenza), on the other hand, tends to hit harder and faster, causing high fever, body aches, chills, fatigue, and headaches. While colds rarely lead to serious health issues, the flu can result in complications like pneumonia, especially in high-risk groups.

Because symptoms can overlap, it's not always easy to tell which illness you have—or whether something else might be going on. If you're feeling unwell and unsure of the cause, take a free, instant, online symptom check to get personalized insights based on your symptoms and guidance on what to do next. It only takes a few minutes and could help you make smarter, faster decisions about your health.

Reviewed for medical accuracy: 07/20/2026

Important Next Steps

Learn if cold or flu fits symptoms Discover likely causes of your cold symptoms See if flu symptoms need care today Find OTC relief for cold symptoms Find a doctor for flu symptoms Discover home remedies for cold or flu Understand if symptoms need urgent evaluation

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Explanation

The common cold and the flu can seem similar at first, but there are key differences. The common cold often starts with a sore throat, followed by a runny or stuffy nose. Symptoms are usually mild and can last for a few days.

The flu, on the other hand, tends to hit you harder and faster. You might experience a high fever, body aches, and extreme tiredness. These symptoms can be more intense and last longer than a cold.

Key Differences:

Onset:
- Cold: Gradual
- Flu: Sudden
Fever:
- Cold: Rare
- Flu: Common, often high
Body Aches:
- Cold: Mild
- Flu: Severe

Recognizing these differences can help you understand what you might be dealing with. If you're unsure about your symptoms, try our free AI symptom checker to get personalized insights and determine if you need to see a doctor.

(References)

Eccles R. (2005). Understanding the symptoms of the common cold and .... The Lancet. Infectious diseases, 16253889.
Prior L, Evans MR, & Prout H. (2011). Talking about colds and flu: the lay diagnosis of two .... Social science & medicine (1982), 21186076.
Czubak J, Stolarczyk K, Orzeł A, Frączek M, & Zatoński T. (2021). Comparison of the clinical differences between COVID-19 .... Advances in clinical and experimental medicine : official organ Wroclaw Medical University, 33529514.

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