Infections / 26.03.2025

common-cold-versus-flu.jpg   The cold winter months are notorious for all kinds of viral and bacterial illnesses to spread, with   Influenza (flu) and the common cold the two most prevalent and contagious respiratory illnesses. Although they may share many of the same symptoms, they are caused by different viruses. The flu is caused by influenza viruses only while the common cold is caused by a number of different viruses. Despite their similarities, knowing the difference between the two is important for the right diagnosis and treatment.

Causes of the Common Cold vs. Flu

The common cold is predominantly caused by rhinoviruses, while viruses such as parainfluenza and seasonal coronaviruses can also be responsible. However, these strains of coronaviruses are not the same as SARS-CoV-2, the virus that causes COVID-19. Rhinoviruses spread through respiratory droplets when an infected person coughs, sneezes, or talks. They can also be contracted by touching an infected person (shaking hands, kissing) or contaminated surfaces and then touching the nose, mouth, or eyes.  The flu is caused by influenza viruses, types A, B, C, with Influenza A and B the most common strains that are responsible for seasonal flu outbreaks. Like colds, the flu spreads through respiratory droplets and surface contact, but it tends to be more severe and can lead to serious complications such as pneumonia, bronchitis, and worsening of chronic conditions like asthma, heart disease and diabetes.