What is the flu?

The flu is an infection caused by the Influenza virus and typically has a sudden onset, with more intense symptoms.

Main characteristics:

  • High fever (usually above 38°C)

  • Body and joint pain

  • Headache

  • Intense fatigue (prostration)

  • Dry cough

  • Chills

A person usually feels like they were "knocked down" from one day to the next. In some cases, especially in elderly individuals, children, and people with comorbidities, it can progress with complications such as pneumonia.

What is a cold?

A cold is caused by different viruses (such as rhinovirus) and tends to be milder, with a gradual progression.

Main characteristics:

  • Runny nose (nasal discharge)

  • Sneezing

  • Nasal congestion

  • Mild sore throat

  • Absent or low fever

  • Mild malaise

Unlike the flu, a cold generally does not prevent daily activities.

Main differences in practice

  • Onset:
    Flu → sudden
    Cold → gradual

  • Fever:
    Flu → common and high
    Cold → rare or mild

  • Symptom intensity:
    Flu → more intense
    Cold → milder

  • Impact on the body:
    Flu → can cause significant indisposition
    Cold → generally tolerable

⚠️ When is it important to seek medical evaluation?

Some signs deserve more attention, especially if you suspect the flu:

  • High fever persisting for more than 3 days

  • Shortness of breath or difficulty breathing

  • Chest pain

  • Worsening of symptoms after initial improvement

  • Patients with chronic diseases, elderly individuals, or small children

💡 What to do?

Both for the flu and the common cold, treatment is mainly supportive:

  • Adequate hydration

  • Rest

  • Fever and pain control with prescribed medications

  • Avoid inappropriate self-medication (especially antibiotics)

Annual flu vaccination is one of the main forms of prevention, especially for at-risk groups.

Although flu and cold are common, understanding the difference helps recognize warning signs and prevent complications.

This content is informative in nature and does not replace individualized medical evaluation. In case of doubt or persistent symptoms, consult a healthcare professional.

Dr. Rebeca Soares Andrade. CRM-GO 39335