What Is the Flu? A Seasonal Threat with Serious Impact
Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses. It affects the nose, throat, and sometimes the lungs, and spreads easily through coughing, sneezing, or contact with contaminated surfaces. While many people recover within a few days, the flu can cause severe illness or death, particularly in vulnerable populations such as young children, the elderly, pregnant women, and those with chronic health conditions.
Every year, flu season brings waves of infection that strain healthcare systems. Seasonal flu epidemics result in millions of illnesses, hundreds of thousands of hospitalizations, and tens of thousands of deaths globally. Despite being preventable through vaccination, influenza continues to pose a significant public health challenge.
Ongoing clinical research plays a key role in developing more effective vaccines, antiviral medications, and strategies to better predict and respond to seasonal outbreaks.
Symptoms of the Flu
Flu symptoms typically appear suddenly and can range from mild to severe. The onset is often abrupt, distinguishing it from other respiratory infections like the common cold.
Common Flu Symptoms:
- High fever or chills
- Cough (usually dry)
- Sore throat
- Runny or stuffy nose
- Muscle or body aches
- Fatigue and weakness
- Headache
- Nausea, vomiting, or diarrhea (more common in children)
Severe Flu Symptoms:
- Shortness of breath or chest pain
- Persistent dizziness or confusion
- Seizures
- Worsening of chronic medical conditions
- In infants: difficulty feeding, irritability, or bluish skin color
Most healthy individuals recover in a week or two, but complications such as pneumonia, bronchitis, sinus infections, and heart inflammation can arise, especially in high-risk groups.
