What is Influenza? (Introduction)

Influenza, or flu, is a contagious respiratory illness caused by influenza viruses. It infects the nose, throat and lungs. It can range from mild to severe and sometimes leads to hospital care or death, especially in high-risk groups.

How it differs from a cold

• Flu usually starts suddenly, with fever, body ache, headache and extreme tiredness.
• A common cold is usually milder, with a runny nose and sneezing, and develops gradually.
• COVID-19 and flu can look alike, and only a test can tell them apart.

How it spreads

• Droplets from coughing, sneezing and talking
• Touching surfaces with the virus and then the face
• A person can spread flu from about a day before symptoms to about 5 to 7 days after.

How long it lasts

Most people recover in about a week. Cough and tiredness can last 2 weeks or more.

Who is at higher risk of serious illness

• Children under 5, especially under 2
• Adults aged 65 and over
• Pregnant women
• People with asthma, diabetes, heart, lung, kidney or liver disease
• People with weak immunity

Seasons

Flu occurs in seasonal waves. In India, peaks often occur with the monsoon and in winter, depending on the region.

Ayurvedic view

Ayurveda describes fever with cough and body ache under jwara and related conditions such as pratishyaya. This is an interpretive framework and not a proven match.

Key point

Flu is more than a bad cold. Vaccination, rest and early care for high-risk people matter.

Before your appointment

Note when symptoms began, your highest temperature, and any cough, breathing trouble or vomiting. List your medicines, long-term conditions, pregnancy, allergies and recent vaccines, including this year's flu vaccine. Mention contact with anyone who is ill. Ask about testing, antivirals, when to return to work or school and the warning signs that mean you should call 112 or 102.