Influenza, commonly known as the flu, is a contagious respiratory illness caused by the influenza virus. It can affect people of all ages and can have a significant impact on public health. The flu virus spreads easily through respiratory droplets when an infected person sneezes, coughs, or talks. It can also be contracted by touching surfaces contaminated with the virus and then touching the mouth, nose, or eyes.

Symptoms of the flu can vary but often include sudden onset of fever, cough, sore throat, stuffy or runny nose, body aches, fatigue, and sometimes vomiting or diarrhea. Most people recover from the flu within a week or two, but some, especially young children, older adults, and individuals with underlying health conditions, may develop complications that can be severe or even life-threatening.

Preventing the flu is important and can be done through various measures. Vaccination is the most effective way to protect against the flu and is recommended for everyone aged six months and older. It helps the body develop immunity to the virus, reducing the severity of illness if infection does occur. Other preventive actions include practicing good hand hygiene by washing hands frequently with soap and water, avoiding close contact with sick individuals, covering coughs and sneezes, and staying home when feeling unwell.