Published: February 4, 2025
Estimated reading time: 4 minutes
Influenza, or the flu, is a common respiratory infection caused by a virus that infects the nose, throat and lungs. Most people can clear the flu on their own. Sometimes there are complications of the flu, such as pneumonia. Pneumonia is an infection in the air sacs of one or both lungs and can be caused by viruses, bacteria or fungi.
The flu is common in during certain times of the year. This is called flu season. The North American flu season typically occurs from October to May. During this time, respiratory infection rates are high, and more people are at risk of catching and spreading these illnesses. Influenza is different from stomach flu, which commonly causes nausea, vomiting and diarrhea.
The most common flu symptoms are:
It spreads through tiny droplets that come out of our mouths or noses when we speak, cough or sneeze. It may be possible to get the flu from touching a contaminated surface.
There are almost 3 million cases of flu each year in the United States, and thousands of flu-related deaths. Some factors may increase your risk for experiencing complications, including:
There are more than 30 causes of pneumonia, which are grouped by type. The types are:
Symptoms of pneumonia include:
Pneumonia is a common complication of flu. The body’s immune system has been working to combat the flu, and that weakens its ability to fight off another illness. The highest-risk groups are children under 5, adults over age 65, pregnant people, and those with chronic medical conditions or an otherwise weakened immune system. Normally, flu symptoms can be treated at home, but you should be aware of worsening symptoms.
You are also more likely to develop pneumonia after flu if you smoke, have asthma or diabetes, or have a BMI over 40.
If your flu symptoms are not getting better, be cautious, especially if you have another chronic condition or have compromised immunity. Pneumonia symptoms may develop a few days after flu symptoms and may appear to mimic flu symptoms. Seek immediate medical attention for:
There are vaccines for both the flu and pneumonia. It’s important to get a flu vaccine every year, as the virus changes and flu shots are reformulated for strains expected to be most prevalent. Talk to your doctor about the pneumonia vaccine to see if you should get one and how often. Other ways to prevent the flu, besides vaccines, include good hygiene — such as hand-washing and covering coughs and sneezes. Also, boosting the immune system can reduce infection risk. This includes exercise, a healthy diet and good sleep.
Flu season runs through March, and while it’s best to get your shot early, the vaccine still can provide protection later in the season. Influenza vaccine is available across Louisville and Southern Indiana. If you think you have the flu, consult with your health care provider, especially if you are immunocompromised.
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