Flu, Cold, or COVID-19? A Guide to Tell Them Apart

With the arrival of colder weather, it's common to start sneezing, coughing, or feeling generally unwell. Immediately, the question arises: is it just a simple cold, a bad flu, or COVID-19? Although they share symptoms, these three respiratory illnesses are caused by different viruses and have characteristics that can help us distinguish them.

The Common Cold: Mild and Familiar

The cold is the most common and generally the least severe of the three. It is caused by a variety of viruses, mainly rhinoviruses. Symptoms usually appear gradually and include:

Nasal congestion or runny nose
Sore throat
Sneezing
Mild cough

Fever is not common in adults with a cold, and if it appears, it is usually low. The general discomfort is mild, allowing most daily activities to continue. Within a week, most people feel much better.

The Flu (Influenza): More Intense and Sudden

The flu, or influenza, is more serious than a cold. It is caused by influenza A and B viruses. Unlike a cold, flu symptoms appear abruptly and are more intense. Pay attention to:

High fever (above 100.4°F or 38°C)
Intense muscle and body aches
Headache
Fatigue and weakness that can last for weeks
Dry, persistent cough
Chills

The flu forces you to bed and can have serious complications, such as pneumonia, especially in children, the elderly, and people with chronic diseases. Annual vaccination is the best form of prevention.

COVID-19: A Broad Spectrum of Symptoms

COVID-19, caused by the SARS-CoV-2 virus, has the widest range of symptoms, from asymptomatic cases to very severe conditions. Its symptoms can look a lot like the flu, but there are some distinctive clues:

Sudden loss of smell or taste (a very characteristic symptom, although not always present)
Shortness of breath or difficulty breathing
Fever, dry cough, and fatigue are also very common

COVID-19 symptoms can appear between 2 and 14 days after exposure to the virus. Unlike the flu, which usually has a sudden onset, COVID-19 can start more gradually. Given the overlap in symptoms, the only way to confirm the diagnosis is through a test.

How to Act?

When in doubt, it is most prudent to act with caution. If you have symptoms, rest, stay well-hydrated, and keep your distance from other people to avoid spreading the infection. If symptoms are severe, such as difficulty breathing, chest pain, confusion, or a very high fever, seek immediate medical attention.

Knowing these differences helps you get an initial idea of what is happening, but remember that only a healthcare professional can give you an accurate diagnosis. Taking care of yourself and protecting others is always the best option.