If you’re among the 93% of older Americans living with at least one chronic condition¹, you know it takes extra care and effort to manage your health. Then flu season hits—and suddenly there’s another worry to add to the list. Aging alone increases the risk of serious flu-related complications, due to natural declines in immunity. Factor in a chronic condition, and that risk rises even further.

Why do chronic conditions increase flu risk?

During recent flu seasons, 9 out of 10 people who were hospitalized with the flu had at least one pre-existing condition.² That’s because even when they’re well-controlled, chronic health conditions affect how the body responds to infection. When the flu virus takes hold, the immune system has to react quickly and effectively to contain it. That response may be slower and weaker for people with chronic illness.

Several factors are at play here:

• A stressed immune system: Chronic illness can tax the immune system, making it more difficult to fight off infections like the flu.
• Higher levels of chronic inflammation: Many ongoing health conditions are characterized by systemic inflammation, which can worsen during flu illness and lead to complications.
• Lower physical reserves: Living with a chronic condition means your body is already working hard. That leaves less energy to battle infections like the flu and bounce back afterward.

For older adults with chronic conditions, the flu doesn’t just cause new problems—it can make  existing symptoms worse.  They are more likely to be hospitalized and die from flu complications. They may also take longer to recover from a bout with the flu.  

What chronic medical conditions put people at risk for flu complications?

Below is a run-down of health problems commonly linked to flu complications.

Chronic lung disease

For people with chronic lung disease like chronic obstructive pulmonary disease (COPD), asthma, and chronic bronchitis, the flu can be especially dangerous. The virus causes inflammation in the airways, making breathing more difficult and triggering flare-ups of existing symptoms.

People with lung disease who get the flu face an increased risk of:

• Heart attack and stroke
• Gradual loss of lung function
• Permanent physical decline
• Hospitalization and death

Even after the initial flu infection passes, lung symptoms may take weeks to settle down, making everyday activities more challenging.

Heart disease

According to the Centers for Disease Control and Prevention (CDC), roughly half of adults hospitalized with the flu have heart disease (e.g., heart failure, heart valve disorders). This is because fever, dehydration, and inflammation place an added burden on the heart at a time when the body is already under strain.

People with heart disease are 6 to 10 times more likely to have a heart attack and 8 times more likely to have a stroke within the first few days of flu illness.³ They are also at greater risk for permanent physical decline, hospitalization, and death.

These heightened risks can last well beyond the initial infection, too. One study found that in the month after having the flu, people are 4 times more likely to suffer a heart attack and 5 times more likely to have a stroke.⁴ This is why flu prevention is considered part of maintaining heart health—especially for those in high-risk groups.

Diabetes

People with diabetes (34 million+ American adults) are 6 times more likely to be hospitalized for flu complications and 3 times more likely to die from them.⁵ One reason is that the flu can cause erratic blood sugar levels. When you’re sick, the body releases stress hormones that may raise glucose levels, even if you’re eating less.

For adults living with diabetes, the flu can:

• Make blood sugar more difficult to control
• Increase the risk of renal and cardiovascular disease issues
• Increase the risk of dehydration and infection
• Lead to hospitalization more quickly

Recovery from the flu may also take longer for people with diabetes, especially if illness interferes with medication routines or nutrition.

Obesity

Obesity affects both immune response and lung function. Excess body weight can limit how well the lungs expand and make breathing more difficult during a flu infection. Research suggests the flu virus may spread deeper into the lungs more quickly in people with obesity, increasing the chance of serious respiratory illness.

Flu-related risks for those living with obesity include:

• More severe symptoms
• Higher risk of complications like pneumonia
• Longer recovery times and greater fatigue

One study found that people with obesity may shed the flu virus for up to 42% longer than people without this condition.⁶

Other chronic conditions that increase flu risk

Other health conditions raise the risk for severe flu illness and complications, including:

• Kidney disease
• Liver disease
• Blood disorders, like sickle cell disease
• Autoimmune conditions
• Cancer
• Neurologic conditions, such as Parkinson’s disease or dementia
• Weakened immune system, caused by illness or medications like steroids or chemotherapy

What older adults with chronic conditions can do if they get the flu

Early action matters once you develop flu symptoms:

• Seek medical care promptly: Don’t wait to see if symptoms improve on their own.
• Ask about antiviral medications: CDC recommends antiviral treatment for high-risk people who have the flu (or are thought to have the flu). These medications work best when started within 24-48 hours of symptom onset—and they can reduce the severity and length of illness.
• Watch for “flu’s red flags”: Know which flu symptoms are a signal to seek immediate medical attention:
  • Worsening of chronic condition symptoms
  • Difficulty breathing or shortness of breath
  • Pain or pressure in the chest or abdomen that doesn't let up
  • Seizures
  • Persistent dizziness or confusion
  • Severe muscle pain or weakness
  • Lack of urination
• Rest and hydrate: Give yourself adequate time to rest and recover—your body needs energy to heal and recuperate.
• Manage chronic conditions carefully: Continue taking any prescribed medications as directed and monitor your symptoms closely.
• Follow up after recovery: It’s a good idea to schedule a check-in with your health care provider once you’ve recovered from the flu. This can help ensure you’re getting back on track.

Prevention is a key part of chronic disease management

If you’re living with one or more chronic conditions, protecting yourself against the flu and other respiratory viruses is an important part of staying healthy.  One of the best ways to lower your risk of complications is getting an annual flu vaccine. Even if you do get the flu, it can help make your illness milder and your recovery easier.

During cold and flu season, many health care providers recommend a layered approach to illness prevention for older adults:

• Get vaccinated against the flu, COVID, and RSV (respiratory syncytial virus).
• Wear a high-quality mask in crowded indoor spaces.
• Wash your hands frequently.
• Keep your indoor spaces well-ventilated and/or use an air purifier.

Dorothea Vafiadis, Senior Director of NCOA's Center for Healthy Aging, said that even when a flu vaccine isn’t a perfect match to that season’s circulating strains, experts agree it still provides meaningful protection against severe illness, hospitalization, and death.

“No vaccine guarantees you won’t get sick, which is why vaccination works best alongside other preventive steps like staying home when ill and practicing good hygiene, particularly for older adults,” she explained. “Together, these measures can help you stay healthy and protect the people you care about, too.”

Sources

1. Centers for Disease Control and Prevention (CDC). Trends in Multiple Chronic Conditions Among US Adults, By Life Stage, Behavioral Risk Factor Surveillance System, 2013–2023. April 17, 2025. Found on the internet at https://www.cdc.gov/pcd/issues/2025/24_0539.htm

2. National Foundation for Infectious Diseases. Flu and Chronic Health Conditions. Reviewed September 2024. Found on the internet at https://www.nfid.org/infectious-diseases/flu-and-chronic-health-conditions/Facilities Fighting Flu. Flu Facts for People With Chronic Conditions (Fact Sheet).

3. Kosuke Kawai, ScD et al., Viral Infections and Risk of Cardiovascular Disease: Systematic Review and Meta‐Analysis, Journal of the American Heart Association. October 29, 2025. Found on the internet at https://www.ahajournals.org/doi/10.1161/JAHA.125.042670

4. National Foundation for Infectious Diseases. Diabetes and Flu. Found on the internet at https://www.nfid.org/resource/diabetes-and-flu/

5. University of Michigan School of Public Health. Adults Who Are Obese and Have Influenza May Be Contagious Longer. August 6, 2018. Found on the internet at https://sph.umich.edu/news/2018posts/obesity-flu-080618.html