Introduction: Flu and Cold—Not the Same Thing!
Despite significant progress in medicine, the common cold remains a major health issue worldwide. In the United States, around 25 million people visit doctors annually due to upper respiratory infections. Cold-related issues cause a loss of 20 million workdays and 22 million school days each year.
However, “the common cold” isn’t a single disease. It’s a group of upper respiratory infections caused by different pathogens. Even today, about 20-30% of cold cases don’t have a known virus origin.
Recently, flu has been making headlines. More people are experiencing symptoms, but the flu hasn’t reached the levels of previous years. The National Health Commission of China announced on January 12, 2025, that the flu is at a relatively high incidence, though it hasn’t surpassed last year’s peak. 
This raises an important question: Why do more people seem to be getting sick, but flu cases haven’t increased dramatically?
Let’s clarify the key differences between flu and the common cold.
Why Knowing the Difference Matters
In English, “common cold” refers to the typical cold, while “influenza” (flu) is a more serious illness. The term “influenza” dates back to Italy in 1658 when a deadly epidemic killed 60,000 people overnight. People thought it was a punishment from God. The term “influenza,” meaning “influence,” described this devastating illness. Today, we still use “influenza” to describe the flu.
From this history, it’s clear that flu and cold differ significantly in severity. Recognizing the difference is vital to prevent complications and protect public health.
Why Differentiating Flu and Cold is Critical
Neglecting the flu can lead to severe consequences. High-risk groups, such as the elderly or children, may not get timely vaccines or antiviral treatment. This can result in death or long-term complications. For instance, children who skip flu vaccines may face severe complications that can lead to death.
On the other hand, treating a simple cold like flu can lead to unnecessary treatments and strain healthcare resources. Overuse of medical services for minor cold symptoms diverts attention from more serious health concerns.
The Relationship Between Flu and Cold
The flu is just one type of cold. Research from the 1960s-1980s revealed that viruses like adenovirus, parainfluenza virus, and rhinovirus can cause cold symptoms. These viruses share symptoms like nasal congestion, runny nose, cough, and fever.
Until recently, only 25% of cold cases could identify a specific virus due to limited testing methods. With modern tools like PCR, we now know that common cold viruses include the flu, coronavirus, and other respiratory viruses.
How to Quickly Tell if It’s Flu or Cold?
While flu and cold share many symptoms, the flu is usually more severe. Flu infections tend to affect the lower respiratory tract and trigger stronger immune responses, which can lead to serious complications in high-risk individuals, such as the elderly, children, pregnant women, and people with chronic diseases.
Colds are generally milder and self-limiting, but the flu can cause life-threatening illnesses like pneumonia, acute respiratory distress syndrome (ARDS), and even myocarditis. Flu complications are more common and dangerous.
Treatment and Prevention
Treatment for flu and cold depends on the virus involved. For most colds, you can manage symptoms with over-the-counter medications like ibuprofen and acetaminophen. Nasal saline rinses can relieve congestion, and antibiotics may be needed if a secondary bacterial infection, like sinusitis, occurs.
Flu treatment, however, requires antiviral medications like Oseltamivir or baloxavir marboxil, but these must be prescribed by a doctor.
Flu and cold viruses spread in three main ways:
- Contact with contaminated surfaces or secretions.
- Airborne droplets that remain suspended in the air.
- Direct contact with large aerosol droplets from infected individuals.
While the common cold is hard to prevent, flu vaccines can reduce severe impacts. Getting vaccinated is the best way to protect yourself and others from flu complications.
Conclusion: Flu vs Cold
Although flu and cold share similar symptoms, they differ significantly in terms of severity and complications. Flu is a serious illness that can lead to complications, particularly in high-risk groups. It’s essential to get vaccinated and seek early treatment for the flu.
The common cold, however, is generally mild and self-limiting, with most people recovering without medical intervention. Knowing the difference between flu and cold can help protect yourself, your family, and the community while avoiding unnecessary medical resources.
