Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses. It primarily affects the nose, throat, and lungs. There are several types of influenza viruses, with types A and B being the most common causes of seasonal flu epidemics. The flu is different from a cold; it usually comes on suddenly and ranges from mild to severe, and can sometimes lead to hospitalization or even death, particularly in high-risk groups like young children, elderly people, and those with weakened immune systems.
Symptoms of the flu often appear suddenly and can include fever, chills, muscle aches, cough, congestion, runny nose, headaches, and fatigue. Some people may experience vomiting and diarrhea, though this is more common in children than adults. The fever and aches typically last for three to five days, while the cough and fatigue can persist for a week or more. The severity of these symptoms can vary widely from person to person and can often be confused with symptoms of other respiratory illnesses, making diagnosis sometimes challenging without specific testing.
Treatment for the flu mainly focuses on supportive care to relieve symptoms. This includes staying hydrated, resting, and taking over-the-counter medications like acetaminophen or ibuprofen to reduce fever and body aches. Antiviral medications may be prescribed for some patients, particularly those at higher risk for complications, to help reduce the severity and duration of symptoms if taken early in the course of the illness. Preventive measures, such as getting an annual flu vaccine, practicing good hand hygiene, and avoiding close contact with sick individuals, are also crucial in managing the spread of the flu.