It is a common misnomer used by the people “I have flu”.
Cold/common cold and Flu are two separate illnesses caused by different viruses. As the symptoms for both illnesses are mostly similar, it is rather difficult to diagnose on the basis of symptoms.
Flu causes intense symptoms and can lead to development of some severe complications. Symptoms of common cold, in comparison, are rather mild. Additionally, the Flu vaccine targets the “Flu” and not the common cold.
Common Cold
It is caused by multiple viruses, including seasonal coronavirus (different from Covid-19 infection), rhinoviris, RSV and parainfluenza amongst others. Typical symptoms are runny or stuffy nose, sneezing, mild body aches, sore throat, cough, lethargy/general feeling of being unwell. The condition is self-limiting and resolves within 7 to 10 days. It can be associated with earache or sinusitis. Treatment is only symptomatic.
Flu (Influenza)
It is caused by Influenza (A & B) virus. Symptoms range from mild to severe, leading to serious complications and at time leading to death. Not all the patients suffering from Flu will develop complications.
Mild symptoms like runny or stuffy nose, sore throat, cough, fever & chills, vomiting, diarrhea, fatigue & body aches. Generally, recovery from such mild symptoms is from few days to less than 2 weeks.
Moderate symptoms are due to complications which develop due to superimposed bacterial infections causing ear or sinus infections. Serious complication include pneumonia which can be either due to the Influenza virus or a secondary superimposed infection caused by bacteria.
People at risks are those with age more than 65 years, having co-morbid/chronic illness like Asthma, COPD, Diabetes, kidney disease, heart conditions, neurological disorders, and immunosuppressive illnesses. Such group pf people are encouraged to get their Flu shots every year to keep themselves protected.