What is the Flu?
Influenza (flu) is a contagious respiratory illness caused by influenza viruses. There are two main types of flu viruses: types A and B. These viruses spread to people throughout the year and are responsible for the seasonal flu epidemics during the fall and winter months. Flu and COVID-19 are both contagious respiratory illnesses, but they are caused by different viruses. COVID-19 is caused by infection with a coronavirus (called SARS-CoV-2) first identified in 2019, while flu is caused by infection with influenza viruses. Because some of the symptoms of flu and COVID-19 are similar, it may be hard to tell the difference between them based on symptoms. Testing for either virus may be needed to confirm a diagnosis.
The most important step in preventing the flu is to get a flu shot each year – and this is not the year to skip it! The Centers for Disease Control and Prevention (CDC) recommends a yearly flu vaccine for everyone 6 months of age and older as the first and most important step in protecting against this serious disease. Flu vaccines have been updated to better match circulating viruses for the 2022 – 2023 flu season. Vaccination is particularly important for people who are at high risk of serious complications from influenza. Please speak with your healthcare provider for more information on vaccination recommendations.
How Flu Spreads
Flu viruses are spread mainly by droplets made when people sick with flu cough, sneeze or talk. These droplets can land in the mouths or noses of people who are nearby. Less often, a person might also get the flu by touching a surface or object that has the flu virus on it and then touching their own mouth, nose, or possibly their eyes.
How long can someone spread the flu virus to others?
People with flu are most contagious in the first 3-4 days after their illness begins. However, some people can infect others before symptoms develop and up to 5-7 days after becoming sick. Some people, especially young children and those with weakened immune systems may be able to infect others for longer than 7 days.
Signs and Symptoms of Flu
People who have the flu often have some or all of these signs and symptoms:
- Fever or feeling feverish/chills (not everyone with flu will have a fever.)
- Cough
- Sore throat
- Runny or stuffy nose
- Muscle or body aches
- Headaches
- Fatigue (very tired)
- Some people may have vomiting and diarrhea, though this is more common in children than adults.
High Risk for Developing Flu-Related Complications
The below health and age factors are known to increase a person’s risk of getting serious complications from flu:
- Children younger than five, but especially children younger than two years old
- Adults 65 years of age and older
- Pregnant people
- People who have pre-existing medical conditions such as asthma, heart disease, and diabetes
- Residents of nursing homes and other long-term care facilities
- People who are immunocompromised due to disease or medications
Tips for Staying Healthy During Flu Season
- Wash your hands often with soap and water for at least 20 seconds; if soap and water are not available, use an alcohol-based hand sanitizer that contains at least 60% alcohol
- Get a flu vaccine
- Practice other good habits such as getting plenty of sleep, being physically active, managing stress, drinking plenty of fluids, and eating nutritious food
- Clean and disinfect frequently touched objects and surfaces
- Cover your cough or sneeze with a tissue, then throw the tissue in the trash
- Stay home when you are sick
- Avoid close contact with people who are sick
- Avoid touching your eyes, nose, and mouth with unwashed hands
