Flu: Who Is Most at Risk?
Conditions That Can Put You at Higher Risk for Complications
Updated October 2023
During flu season, you may see stories about seemingly healthy people who lost their life to influenza, or “flu.” While it is rare for otherwise-healthy people to die from flu, certain conditions can put you at higher risk for suffering severe complications from the illness.
How Flu Affects Older Adults
“Influenza seasons vary in severity. During most seasons, people 65 years and older bear the greatest burden of severe flu disease,” says Douglas L. Ambler, MD, an internal medicine physician at Northwestern Medicine.
According to the Centers for Disease Control and Prevention (CDC), it is estimated that between 70% and 85% of seasonal flu-related deaths have occurred in people 65 years and older, and between 50% and 70% of seasonal flu-related hospitalizations have occurred among people in this age group.
Dr. Ambler offers five key reasons why it is important to get a flu shot after age 65:
- Older adults are at higher risk of complications from the flu, including hospitalization and death.
- Older adult populations often have associated comorbidities like chronic obstructive pulmonary disease (COPD) and congestive heart failure, which put them at higher risk for complications related to the flu.
- Older adults tend to have impaired immune systems compared to younger patients, which can make them more susceptible to complications and severe illness.
- If you live in an older adult community, such as an independent living, assisted living or nursing home environment, you are more at risk since you live in a community where the flu can spread more rapidly.
- People who get a flu shot have a lower risk of being hospitalized for the flu or being admitted to an intensive care unit (ICU), and they have a lower risk of stroke and heart attack during the flu season.
“All adults over age 65 should get a high-dose flu shot starting anytime in September and preferably by the end of October. You can get it later, but it is best not to wait,” adds Dr. Ambler. “You can also get a flu shot with your pneumonia vaccine and with your COVID-19 booster shot as well.”
How Flu Affects Babies and Young ChildrenIn children birth to 5 years old, influenza is more likely to cause severe illness and a bacterial co-infection. Lubna S. Madani, MD, a family medicine physician at Northwestern Medicine Immediate Care Glen Ellyn, says children in this age group are at higher risk of flu complications because:
- Their anatomy does not allow congestion to drain as well, and children can have fluid in the ear that eventually can grow bacteria.
- Young children, especially those who are frequently around other children, such as in a daycare setting, can carry bacteria in their noses. This bacteria may not pose a threat when the child is healthy, but if a virus such as flu infects the child, that bacteria can cause a secondary bacterial co-infection that can be severe and possibly fatal.
“Because the virus is spread through droplets, children may be more prone to spreading the flu because they are more prone to touching their noses, and poor hand-washing,” says Dr. Madani.
Therefore, Dr. Madani suggests giving them an immunization and teaching children to:
- Cover their mouth and nose while coughing or sneezing, and make sure they throw away dirty tissues immediately.
- Sneeze or cough into the sleeve of their clothing at the inner elbow to contain sprays of saliva and secretions and to avoid contaminating their hands.
- Wash their hands often with soap and water, especially after their cough or sneeze.
- Avoid touching their eyes, nose or mouth, as germs are often spread this way.
How Flu Affects Pregnant People
People who are pregnant or who have recently given birth experience changes in their immune system, heart and lungs. Therefore, according to the CDC, they are more likely than people who are not pregnant to have severe illness from flu and should get a flu shot to avoid complications. Those who are pregnant and who get the flu may develop dehydration or high fever, which puts their unborn babies at risk. Unborn babies may be more likely to experience neural tube defects or other adverse conditions if they are exposed to fever in the womb.
According to the CDC, vaccination has been shown to reduce the risk of flu in pregnant people by up to one-half. It can also help protect babies from flu illness for the first several months after their birth, when they are too young to get vaccinated.
How Flu Affects People With Cancer or Other Serious Illnesses
People with chronic disease or who have weakened immune systems are also at higher risk for contracting and developing serious illness from flu. Among those who may be at higher risk for complications from flu:
- People who have cancer or a history of cancer, and those with autoimmune disorders, due to a weakened immune system
- People with asthma, because of the risk of triggering asthma attacks
- People with a history of heart disease or stroke, since flu can lead to inflammation in the body that could trigger a worsening of existing conditions
- People with diabetes, as it can affect the ability to control blood sugar
If You Get Sick
Flu should be suspected if you develop symptoms, such as a fever or feeling feverish accompanied by muscle aches, headache and/or fatigue. If you think you have flu:
- Seek medical care early. Antiviral medication may help shorten the length of the illness and decrease its severity, but the medication needs to be administered early in the illness to be most effective.
- While antibiotics can’t cure flu, it is also possible for influenza to lead to other types of infection or conditions caused by bacteria that could be treated with an antibiotic.
Stay home. Your body needs rest. Staying away from other people will help prevent the illness from spreading and possibly infecting someone who is particularly vulnerable.