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Ketones + The Flu: What to Know and Do

Written by: Kourtney Johnson

4 minute read

November 10, 2025

When you live with diabetes and are sick with the flu or a virus, a big concern is developing ketones. But often, the signs and symptoms of elevated ketones can be mistaken for symptoms of the flu, so it’s important to stay aware!

Ketones, which develop when the body lacks insulin and starts burning fat for energy, make the blood acidic. If not treated, they can lead to diabetic ketoacidosis (DKA). DKA can cause serious problems like swelling of the brain, loss of consciousness, diabetic coma and even death.

Continue reading to learn more about the signs of rising ketone levels, how to avoid them and how to treat them.

Signs that Ketones are Present

Keep an eye out for signs of rising ketones—they can be very similar to (and often mistaken for) symptoms of the flu! 

Early signs include: 

  • being very thirsty
  • urinating a lot more than usual

If untreated, more severe signs include:

  • nausea
  • vomiting (throwing up)
  • having abdominal (stomach) pain
  • having fruity-smelling breath
  • being very tired 
  • muscle stiffness or aches 
  • headache
  • flushed face 
  • dry skin and mouth 
  • fast, deep breathing 

Keep in mind, ketones can also be present when blood sugar levels are normal, especially when sick and while taking certain medications like SGLT-2s. 

If you’re unsure if it’s ketones or the flu, take a urine or (even better) a blood test

With most types of ketone tests, results fall into four different categories:

  • Normal or negative ketones 
  • Low to moderate ketones 
  • High ketones 
  • Very high ketones 

Best Tips to Avoid DKA During the Flu

Even though illness increases the risk of having ketones, there are ways to avoid DKA. 

  • Have a ketone management plan in place with your healthcare provider.
  • Check your glucose often, either with a continuous glucose monitor (CGM) or blood glucose meter (BGM). 
  • Keep your glucose in range as much as possible.
  • Take medications as prescribed. 
  • Stay hydrated and replace your electrolytes—Gatorade is a good option. 

What to Do If You Have Elevated Ketones

If you do have ketones, there are steps you can take to manage them. 

Contact your healthcare provider (HCP) if you have signs of DKA or your ketone test shows that you have moderate or high ketone levels.

Follow your HCP’s instructions for insulin doses (which will likely need to be increased) and other treatment measures. 

Check your blood sugar level every hour to make sure it is decreasing. Test ketones regularly to ensure they are decreasing as well. 

Drink plenty of fluids—including sugar-containing ones if you aren’t eating much—to stay hydrated. If you can tolerate food, eat every couple of hours.

Do not exercise when you have ketones. Physical activity can raise both blood sugar levels and ketones.

The Bottom Line

Being sick isn’t fun, especially with diabetes. But glucose management is key in order to manage ketones and prevent DKA. 

It’s best to be cautious and maintain contact with your healthcare provider so you feel better as soon as possible! 

To learn more about ketones and DKA, visit RisingKetones.com.

 

This content was made possible by Abbott Diabetes Care, an active partner of Beyond Type 1. Beyond Type 1 maintains editorial control over its content.

 

Author

Kourtney Johnson

Kourtney is a registered dietitian living with type 1 diabetes. She was inspired to study nutrition after learning about the role food plays in managing this condition. When she's not writing about all things food and diabetes-related, she enjoys reading, cooking, traveling, going to the beach and spending time with loved ones.