Can You Die From the Flu? What To Know About Severe Influenza

Tens of millions of people in the U.S. get the flu each year. And most of them get over it in a week (or three). But that doesn’t mean you should underestimate this seasonal virus.

We asked infectious disease specialist Dhatri Kotekal, DO: Can the flu kill you? Here’s what you need to know.

Can the influenza virus kill you?

The short answer is yes: The flu virus can kill you.

But understanding what makes it dangerous, knowing the symptoms to look out for and getting help at the first sign of trouble can help you avoid complications.

How does the flu become life-threatening?

While it’s true that the illness from a severe flu virus can be life-threatening, most deaths are triggered by secondary infections or medical issues.

“Fighting off the infection also puts major stress on your body,” Dr. Kotekal explains. “That can lead to all sorts of complications, some of them deadly.”

Examples include:

• Pneumonia: The flu can cause pneumonia in two different ways. First, the influenza virus can spread to your lungs, causing viral pneumonia. Second, it can weaken your immune system, making it easier for a secondary bacterial infection to take hold. Dr. Kotekal calls pneumonia “the No. 1 complication” seen from the flu.
• Sepsis: Sepsis is a life-threatening response to an infection like the flu. “Your immune system can become so overactive that it starts damaging normal, healthy organs and tissues,” Dr. Kotekal explains.
• Cardiovascular complications: If you’re living with heart disease, a bad case of the flu can affect your heart rate, rhythm and blood pressure. In severe cases, it can trigger a heart attack, stroke or myocarditis. It can also worsen heart failure.
• Respiratory complications: The flu can cause lung conditions like asthma and COPD to flare up. It can be especially dangerous if you’re living with lung cancer. These complications can lead to respiratory failure and ventilator use.

Is influenza A dangerous?

Generally speaking, influenza A causes more hospitalizations and deaths than influenza B. But influenza B is potentially deadly, too.

“On an individual level, complications from A and B often look similar,” Dr.Kotekal says. “At a population level, the difference is a bit clearer.”

The 1918 influenza pandemic and the 2009 swine flu pandemic? Those were both influenza A. Bird flu is also a type of influenza A.

Influenza B circulates yearly like influenza A, but it tends to have a smaller impact.

Which flu is more dangerous: influenza A or B?

While influenza A tends to make headlines for being dangerous, Dr. Kotekal warns against underestimating influenza B.

According to the U.S. Centers for Disease Control and Prevention (CDC), anywhere between 6,300 and 52,000 people in the U.S. die as a result of the flu each year.

“Flu can be deadly, regardless of which type you’re dealing with,” she notes. “That’s why it’s important to take preventive measures every respiratory season.”

Who is at most risk of complications?

Your risk for developing severe flu complications increases if you have chronic health conditions, such as:

• Asthma
• Chronic obstructive pulmonary disease (COPD)
• Diabetes
• Heart disease
• Kidney disease
• Lung disease
• Obesity

People at opposite ends of the age spectrum — those younger than 5 years old or older than 65 — also tend to be more vulnerable to flu-related complications. Ditto for those who are pregnant.

Can healthy people get severe influenza?

“Perfectly healthy people can get severe complications from influenza,” Dr. Kotekal reports. “It’s less likely, but it can absolutely happen.”

And doctors sometimes discover an underlying health condition, like high blood pressure or a clotting disorder, when flu complications send you to the hospital.

What are the warning signs of severe flu?

There are many red flags that a case of the flu is becoming dangerous. But Dr. Kotekal says one of the clearest is feeling better — only to have your symptoms come roaring back.

“This often means that you’ve developed a secondary infection like pneumonia,” she explains. “That’s a clear sign to call your provider or, for severe symptoms, go to the emergency department.”

Treat the flu as an emergency if you’re experiencing:

• Difficulty breathing or shortness of breath
• Chest pain, tightness or pressure
• Bluish lips, face or fingernails
• High fever
• Signs of dehydration like extreme weakness, dry mouth and peeing very little
• Severe vomiting
• Confusion or dizziness
• Fainting or trouble staying awake

The warning signs of severe flu look a bit different in children under 5 years old. Get help if your little one has the above symptoms, but also keep an eye out for:

• Fever over 100.4 degrees Fahrenheit (38 degrees Celsius) in infants under 3 months old
• Fever over 102 degrees Fahrenheit (38.9 degrees Celsius) in kids between 3 months and 3 years old
• Skin rash
• Breathing that’s faster than usual
• Difficulty waking them
• Inconsolable crying or irritability

“When it comes to the flu, it’s always better to be safe than sorry,” Dr. Kotekal emphasizes. “Reach out to your provider or go to an urgent or express care if you need help deciding next steps.”

How quickly can it become serious?

If you have an underlying condition, the flu can get very serious very fast — sometimes in as little as 24 or 48 hours.

That’s why it’s important to protect yourself against the virus. That means washing your hands throughout the day, practicing good cough etiquette and routinely disinfecting the surfaces in your home.

Consider getting vaccinated, too. Studies show that a flu vaccine can lower your chances of catching the virus — and if you do get it, you’re less likely to get seriously sick.

Healthcare providers usually recommend that people over 6 months old get a flu shot in September or October. A provider can help you decide what’s best for you and your family.

Of course, a vaccine won’t help if you’re already sick. So, how else can you prepare?

“If you’re high risk for complications, consider buying an at-home flu test when respiratory season starts,” Dr. Kotekal advises. “If you have symptoms, test yourself. If it comes back positive, call your primary care provider immediately so you can start treatment.”

How is it treated?

Some flu complications and secondary infections — like strep throat or mild pneumonia — can be managed on an outpatient basis with medications, fluid and plenty of rest.

But when the flu triggers a life-threatening complication, like sepsis or organ failure, you need emergency treatment at a hospital. That may include interventions like:

• IV fluids
• Antiviral medications
• Antibiotics (for secondary infections)
• Oxygen therapy
• Monitoring in the intensive care unit (ICU)

“Flu complications can be scary, and it’s sometimes hard to know if your illness is an emergency,” Dr. Kotekal acknowledges. “If you’re on the fence, call your primary care provider or go to an urgent or express care. The sooner you seek medical advice, the better the chances of a good outcome.”