Diabetes and the Flu: What You Need to Know

People with diabetes are at an elevated risk for flu complications, making the flu vaccine imperative. Check out this expert insight for preventing the flu and recovering if you end up getting sick.

mature Black woman with a fever and flu
Fever is one of several potential symptoms of the flu.Shutterstock

The 2022–2023 flu season could start earlier and be more severe than in years past. As a result, public health officials and doctors alike are urging people with underlying health conditions such as diabetes, who are at risk for more serious complications, to get their flu shots as soon as possible.

“The flu shot is already available, so I would highly recommend people with diabetes get them as soon as they can,” says Hanah Polotsky, MD, an endocrinologist and internist at Kaiser Permanente in Denver.

Influenza, commonly known as the flu, is a respiratory virus affecting an average of 8 percent of Americans each year, according to the Centers for Disease Control and Prevention (CDC). The flu causes symptoms such as fever, cough, sore throat, and runny nose, and can progress to more serious illnesses, such as pneumonia, and death.

Tips to Prevent the Flu and Pneumonia

Nobody wants to get the flu or pneumonia, especially if you have diabetes. Here are a few ways to protect yourself!
Tips to Prevent the Flu and Pneumonia

“People with diabetes have difficulty fighting off all sorts of infections, and likewise have difficulty mustering an appropriate inflammatory response to fight off an early pneumonia,” says William Schaffner, MD, medical director for the National Foundation for Infectious Diseases (NFID) and professor of medicine at Vanderbilt University School of Medicine Center in Nashville.

How the Flu Can Affect People With Diabetes

The flu virus infects cells at the back of the nose and throat, causing congestion or a sore throat. Inflammation of the mucus membranes inside the bronchial tubes, which carry air in and out of your lungs, can cause a cough, Dr. Schaffner says.

Inflammation also creates an opportunity for bacteria, normally present in our throats, to infect the lungs themselves, called pneumonia, says Schaffner. This can cause difficulty breathing, a cough, and chest pain, and, if not treated, it may become deadly.

A more serious infection like pneumonia can make it hard to control blood sugar, which can increase the risk of diabetic ketoacidosis, a dangerous health emergency where the blood contains high levels of ketones, says Schaffner. People with type 2 diabetes are more likely to be overweight, an added risk factor for respiratory diseases such as pneumonia.

How to Prevent the Flu and Its Complications

Getting a yearly flu vaccine is the best way to prevent flu and its complications, say Schaffner and Dr. Polotsky. During the 2019 to 2020 season, flu vaccines prevented 7.5 million flu illnesses and 6,300 flu-related deaths, according to the CDC.

Scientists develop a new flu vaccine each season to closely match circulating viruses and its efficacy can therefore vary, anywhere from 19 to 60 percent from 2009 to 2022, according to CDC data.

Keep in mind that getting vaccinated is beneficial even if you get the flu. In 1,670 people with diabetes, getting a flu vaccine reduced hospitalizations for the flu by 46 percent, compared with not getting a flu vaccine, according to a study published in July 2021 in Clinical Infectious Diseases. In a separate study published in 2021 in Vaccine, among people who went to the hospital for the flu, adults who were vaccinated had a 26 percent lower risk of being admitted to the intensive care unit and a 31 percent lower risk of dying prematurely compared with adults who were unvaccinated.

Schaffner and Polotsky recommend that people 65 and older, including those with diabetes, receive specific flu vaccines such as Fluzone high-dose quadrivalent, Flublok quadrivalent, or Fluad quadrivalent, per recent CDC recommendations.

You can get your flu shot at your doctor’s office or pharmacy, and the CDC’s Vaccines.gov allows you to search for nearby flu vaccine locations by ZIP code. Medicare, Medicaid, and most private health insurance cover the cost of flu vaccination, and some health providers such as local public health agencies offer free flu vaccines.

Tips to Prevent the Flu and Pneumonia

These steps apply to anyone looking to prevent the flu and complications like pneumonia, but they can be especially important for people with diabetes.

  • Get a yearly flu vaccine shot. (Opt for the high-dose version if you’re over age 65.)
  • Ask your doctor or pharmacist if you are eligible for the pneumococcal vaccine, which protects against the bacteria that cause pneumonia.
  • Avoid physical contact with others who are coughing or sneezing.
  • Wash your hands frequently.
  • Flu virus can live for 24 to 48 hours on surfaces, so wash surfaces with soap or other disinfectants.
  • Wear a face mask to indoor events during flu season.
  • Keep tabs on influenza spread in your community, and consider staying home if cases are high.

“The vaccine moves the equation in your favor, but it’s not 100 percent protective, so anything you can do to avoid exposure [to the virus] is a good thing,” Schaffner says.

What to Do if You Get the Flu as a Person With Diabetes

Even when taking precautions, including getting vaccinated, you may still get the flu. Flu can spread when an infected person up to six feet away coughs or sneezes and their infected droplets land in our noses or mouths, according to the CDC. Less frequently, it spreads when you touch a doorknob or other surface infected with the flu virus.

Polotsky says Tamiflu or other prescription antiviral medications can be helpful for people with diabetes, particularly if they are 65 or older, and at higher risk for complications from the flu.

Tips to Recover From the Flu While Managing Diabetes

  • Stay hydrated by drinking plenty of sugar-free fluids like water.
  • If you take insulin, you may need to check your blood glucose levels more often.
  • Be aware of severe low blood glucose episodes, called hypoglycemia, if you take insulin and are not eating as regularly.
  • If you use cough syrup, choose one that is sugar-free.

When to Seek Care From a Medical Professional

Symptoms of the flu typically peak around days 2 to 3, but improve by days 5 to 7, Polotsky says. “If you're coughing more and your fever is persistent, it's a sign of the most common complication from influenza, which is bacterial pneumonia. And that could be very serious.”

Polotsky says you should call your healthcare team immediately if you have those symptoms or any of the others listed below.

Signs or Symptoms of a Medical Emergency

Beware these warning flags:

  • Fainting or passing out
  • Severe chest pain
  • Difficulty breathing
  • Persistent, worsening fever of 101 degrees F or higher
  • Coughing that becomes worse after five to seven days
  • Uncontrollable blood glucose levels

“If you feel sick disproportionately to how you feel when you get a cold and you’re just not getting better, you are always safer to call [your provider] than not to call,” Polotsky adds.

A Final Word on Flu and COVID-19 Vaccines for People With Diabetes

Over the past two years, there have been fewer cases of the flu due to measures adopted during the pandemic such as social distancing and wearing a mask to prevent the spread of COVID-19. Now, people are traveling, going back to work and school, and returning to normal activities that could increase the spread of flu.

In fact, the upcoming season could mean increasing cases of both flu and COVID-19, Polotsky says. Conveniently, you can get both your COVID-19 vaccine or booster at the same time as your flu vaccine, Schaffner says.

The CDC recommends updated bivalent COVID-19 boosters, at least two months out from completion of a person’s primary vaccination or last booster shot, for anyone age 12 or older. Those 12 to 17 years old can only receive the Pfizer bivalent booster.

People with certain medical conditions, such as diabetes, are at higher risk for getting sick, being hospitalized and dying from COVID-19, so it is particularly important to them to stay up-to-date on their vaccinations and booster.

Schaffner says many people have vaccine fatigue, at this point, and are still focused on COVID-19, so he worries about this year’s flu vaccination rates. “We have to make an extra effort to remind people that there’s yet another really nasty respiratory virus out there and it’s the flu,” he says. “For that we also have a vaccine, and you should get both.”