Winter is the season of the two most common respiratory infection:, cold, and flu. Although many people think one can catch a cold or flu by not dressing warmly enough in the chilly weather, there’s more to it. In reality, the actual cause is one of the more than 200 viruses that enter your body and attack your immune system leading to cold or flu.

Flu is a viral infection caused by the influenza virus, whereas common cold is caused by the adenovirus or coronavirus; in fact, there are many subsets of causes for cold and flu.

Cold
Common cold spreads when you inhale virus particles from an infected person’s sneeze, cough, speech, or loose particles that might be in the air when an infected person wipes their nose. This virus easily spreads by touching a contaminated surface that the infected individual has touched. Rhinoviruses, which cause the most colds, can live up to three hours on hard surfaces and your hands. Most viruses can be classified into one of the groups like human rhinoviruses, coronaviruses, parainfluenza viruses, and adenoviruses. Another known cause is the respiratory syncytial virus; many other viruses are yet to be identified.

Flu
Flu season usually runs from fall to spring, peaking during the winter months. Flu is caused when you come in contact with droplets spread by an infected person. The major causes of flu are influenza A, B, and C viruses, with the first two types of influenza being the most common types.

Apart from the above causes, it is equally important to know that the symptoms of cold and flu are also caused by a handful of chemicals in your own immune system. From the moment you breathe in a cold or flu virus, the bacteria starts invading and destroying cells in your body. But this cell destruction isn’t what makes you feel sick; it’s the inflammation that is triggered by the viruses. Due to this inflammation, you will have the symptoms of cold and flu and need proper care.