Dr S P Pradhan on 28th September, 2025
Seasonal flu virus infection are very common causing fever, sneezing, myalgia needs to be differentiated from common cold.
What is Flu?
Flu is known as Influenza. It is a very contagious disease caused by influenza viruses. It affects the nose, throat, and lungs.
Covid 19 infection has similar symptoms like flu; it is caused by Covid 19 virus. But systemic complications like coagulopathy, heart attack are more common in Covid 19 infection.
Types of Influenza Virus?
Influenza viruses are mainly 3 types; type A, B, and C whereas type A is usually the most severe form of virus.
Incubation Period
Incubation period means interval between entry of virus to onset of symptoms. It is usually between 1 to 3 days.
Mode of Transmission
It spreads through droplets of coughing, snzeeing by direct contact or through surfaces.
Symptoms of Flu
Symptoms usually appear suddenly within 1–3 days of exposure:
- Fever and chills
- Cough
- Sore throat
- Runny or stuffy nose
- Muscle or body aches
- Headache
- Fatigue or weakness
Difference from the common cold:
- Flu symptoms are more severe and come on suddenly but common colds are milder and develop gradually.
- Cough is more common in flu.
- Flu often causes high fever, body aches, and extreme tiredness or myalgia which are less common in common colds.
- The best predictors for influenza are cough and fever, since this combination of symptoms has been shown to have a positive predictive value of around 80% in differentiating influenza from a population suffering from flu-like symptoms from common cold.
Complications
Complications are not very common. But still some complications may be seen.
-
- pneumonia
- bronchitis
- Aggravation of Asthma or COPD
- worsening of existing cardiovascular diseases
- Vulnerable groups are young children, older adults, pregnant women, and people with chronic diseases
What to do if you catch Flu or common cold or Remedies for Cure
- Flu is very contagious; it spreads rapidly from person to person. Keep yourself in isolation.
- Take adequate rest.
- Antipyretics like paracetamol can be taken. Special antiviral drugs to be taken after consulting the physician.
- Common colds are self limiting. There is no role of antivirals even though most of the cold are caused by rhinoviruses.
Antibiotics in flu
Flu is a viral disease .There is no role of antibiotics in flu.
How long Flu last
Flu usually lasts for a week. But in cases of low body immunity it may last for two weeks.
When to see a doctor in Flu?
- If patient has high grade fever or persistent cough
- Young children or neonates with risk factors or high grade fever
- Older patients having chronic diseases like diabetes, chronic respiratory illness must attend the physician early
Precautions to avoid infection
- Frequent handwashing,
- covering coughs/sneezes with masks
- avoiding close contact with sick people,
- Isolation of people already diagnosed with flu
- Maintaining good immunity also help; eating lots of green vegetables and fruits can help.
How to Prevent Flu infection?
Flu is an endemic disease; it is constantly present in our environment. Its incidence or rate of infectivity is common in a particularly season.
Those vulnerable population can take annual vaccination.
