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People living with type 1 diabetes (T1D) often hear the words, “diabetic coma” thrown around a lot. Many think that the risk of falling into a diabetic coma is pretty low, and that it only affects people with wildly “uncontrolled” diabetes.

However, people with T1D can fall into a diabetic coma more easily thank you may think — from either a hypoglycemic episode (extreme low blood sugar) OR a hyperglycemic episode (extreme high blood sugar), and they need to walk the tightrope of blood sugar control to prevent either from happening.

This article will outline exactly what a diabetic coma is, how it’s treated, and what you can do to prevent it.

There are three types of diabetic comas: diabetic ketoacidosis (DKA)-induced coma, hypoglycemic coma, and hyperosmolar coma (which mostly affects people with type 2 diabetes, often with obesity). People with T1D are most often affected by the first two, which will be the focus of this article.

The dangers of these conditions cannot be understated: If you fall into a diabetic coma, you are still alive, but are unresponsive and need immediate medical attention to prevent imminent death.

Diabetic ketoacidosis, or DKA for short, is a serious short-term complication of T1D that occurs when the body’s blood turns acidic from an abundance of ketones in the blood, most often resulting from extremely high blood sugar and complete lack of insulin in the body.

DKA is what happens when the body cannot metabolize any sugar or glucose ingested because there is a lack of insulin available. This is a medical emergency and requires immediate attention, as it quickly leads to a DKA-induced coma.

Unfortunately, about 25 percent of newly diagnosed people with T1D are diagnosed when they are already in DKA, which can be life threatening if not immediately addressed.

DKA can have a very quick onset, such as an insulin pump failure or forgetting to take a meal bolus, or it can develop over the course of several days, like when someone is fighting off an illness or infection.

Occasionally, DKA can occur in people without T1D; the condition can be caused by starvation, fasting, alcoholism, or hyperthyroidism, but the majority of cases occur in people with insulin-dependent T1D. DKA can also occur in people with diabetes without elevated blood sugars, which experts believe is most commonly a result of people with T1D taking SGLT2 inhibitor drugs, which were really designed for use with type 2 diabetes.

The following are typical symptoms of DKA. If you or a loved one are experiencing any combination of the below symptoms, along with chronic high blood sugar with moderate to high ketones, seek immediate emergency medical attention, as you can fall into a DKA-induced coma within hours:

  • high blood sugar
  • ketones in the urine
  • dry mouth
  • shortness of breath
  • rapid heart rate
  • fruity smelling breath
  • extreme thirst
  • body ache and headache
  • blurred vision
  • frequent urination
  • nausea
  • vomiting
  • extreme fatigue
  • confusion
  • sudden weight loss
  • flushing of the face

DKA and DKA-induced coma require immediate and professional medical attention, which will usually involve both an intravenous insulin drip along with fluids administered. Medical professionals will want to closely monitor your blood sugars and other vitals such as heart rate, temperature, kidney function, blood pressure, and urine levels as well.

Some cases of DKA require a stay in the intensive care unit (ICU) of a hospital, and many people spend upward of a week recovering.

Suzie Spinks, of Cambridge, Massachusetts, was diagnosed with T1D five years ago. She was in DKA at diagnosis, and had to spend a full week in the ICU.

She says, “It’s true what they say: I really felt like I just had the stomach bug. I kept throwing up and couldn’t keep any food down. I was drinking so much water and urinating so often that eventually I just slept in the bathroom, it was that bad.”

Spinks was extremely close to falling into a DKA-induced coma, with her blood sugar at diagnosis near 500 mg/dL, and her HbA1C at 13.5 percent.

“My mouth was so dry for so long and it felt like I constantly had bad breath even while brushing my teeth. It was terrible!” she said.

If you are experiencing any of the aforementioned symptoms along with high blood sugar (>250 mg/dL) and moderate to high ketones for several hours or days, call 911 or seek immediate emergency medical attention.

DKA-induced coma usually does not set in until someone’s blood sugar has reached at least 600 mg/dL, which is also a medical emergency and needs immediate assistance.

Hypoglycemic coma, on the other hand, is the onset of a coma when one’s blood sugar falls dangerously low. This generally is diagnosed when the person’s blood sugar has fallen below 49 mg/dL and they are unresponsive.

People with T1D are at the highest risk of hypoglycemic coma while they are sleeping, highlighting the importance of continuous glucose monitoring overnight. One study showed that the average person with T1D experiences two episodes of low blood sugar per week!

Hypoglycemic coma can occur due to many reasons, all of which result from extreme, prolonged low blood sugar. These triggers include: miscalculating and taking too much insulin for a meal, accidentally over-bolusing with an insulin pump, not eating enough carbohydrates for insulin taken, participating in extreme exercise and not adjusting insulin settings appropriately, having too much insulin on board (IOB) [insulin taken exogenously that is still active in your bloodstream] while exercising or drinking alcohol, or overdosing on insulin in any form.

This also is an extremely dangerous condition that can lead to death. People who experience hypoglycemia unawareness — who don’t feel the normal warning symptoms of oncoming low blood sugar — are the most at-risk for this type of diabetic coma.

If your blood sugar levels are rapidly lowering and not responding to fast-acting glucose, such as juice, glucose tablets or gels, this is a sign that you are at immediate risk for hypoglycemic coma. The signs and symptoms of an urgent low blood sugar include:

  • confusion
  • sweating
  • rapid heart rate
  • hunger
  • shakiness
  • fatigue
  • irritability
  • nausea
  • dizziness
  • difficulty speaking or communicating
  • muscle weakness

If you are experiencing an urgent low blood sugar (<49 mg/dL) that is not responding to fast-acting glucose, and/or you have too much IOB, call 911 and seek immediate emergency medical attention. This too can be life threatening if not treated.

If you fall into a hypoglycemic coma, a hospital will need to closely monitor not only your blood sugars, but also your vital signs such as heart rate, blood pressure, fluid retention, urine, kidney function, and brain activity as well.

They will immediately give you intravenous glucose and intramuscular glucagon to try and bring your blood sugar levels back up as soon as possible.

A typical hospital stay for hypoglycemic coma can last from several days to a week to even several months, if the condition does not improve.

Most people who fall into a hypoglycemic coma do make a full recovery. However, if the condition is not treated quickly, it can result in irreversible brain injury and even death.

Tricia Phelan, who has been living with T1D for the past 25 years, experienced a diabetic coma from a low blood sugar in her sleep in her upstate New York home several years ago. She says, “The experience was terrifying. My husband noticed that something wasn’t right and gave me a shot of glucagon to wake me up. He then called 911 and I was admitted to the hospital to be monitored for a day.”

“I now always check my blood sugar before bed, and now I won’t fall asleep if I’m under 100 mg/dL,” she said.

How long can a person be in a diabetic coma?

Most people recover quickly after a diabetic coma (both DKA and hyperglycemic coma), and should respond immediately to emergency treatment. However, if either condition is not treated immediately, people can remain in a coma for several days or even months, and some people may even die as a result.

Can a diabetic coma kill you?

Although rare, both DKA-induced coma as well as hypoglycemic coma can and do kill people. It is important to take every step you can to prevent the onset of both severe high and low blood sugars to help prevent these conditions.

Is a diabetic coma painful?

When in DKA, people often feel disoriented, achy, thirsty, and can have debilitating headaches. Severe low blood sugars, while not painful per se, are extremely uncomfortable, with shakiness and disorientation being common symptoms.

In both cases of coma, however, the patient has lost consciousness, and is no longer able to interact with their environment. They do not feel pain outright, but generally feel drained and exhausted after regaining consciousness. Hospital staff make every effort to alleviate any pain the patient may be feeling.

At what sugar level does diabetic coma set in?

There is no set blood sugar at which a person with T1D will fall into a coma; this varies by patient. However, extreme low blood sugars are categorized as anything below 49 mg/dL, which puts patients at higher risk for a hypoglycemic coma, and extreme high blood sugars are anything above 600 mg/dL.

What should you do if someone is going into a diabetic coma?

In either case, call 911 immediately, and seek immediate medical attention. If someone has an extremely low blood sugar and they have emergency glucagon (either an injection kit, injection pen or nasal spray) on hand, use that immediately while you wait for an ambulance to arrive.

It’s important to remember that someone who is experiencing severe low blood sugar may not always be able to chew and swallow, so trying to give them food when they’re losing consciousness can put them at risk of choking. This makes glucagon the best option while you wait for professional medical help to arrive.

While these conditions may not be 100 percent preventable if you have insulin-dependent T1D, there are steps to take to help protect yourself:

  • Wear a CGM that alarms you of both high and low blood sugars.
  • If you experience hypoglycemia unawareness, look into getting a diabetes alert dog.
  • Check your blood sugars often, especially right before going to sleep at night, when you are sick or fighting off an infection, and before, during, and after strenuous exercise.
  • Check your blood sugar 90 minutes after changing your insulin pump site, to make sure the cannula is inserted correctly.
  • Limit alcohol consumption.
  • Avoid excessive alcohol consumption after strenuous exercise.
  • Do not drink alcohol alone.
  • Have an emergency contact who can be reached if you find yourself with a serious low blood sugar and need immediate help.
  • Be sure that friends and family know how to treat low blood sugars if you become unresponsive.
  • Have ketone strips at home, and test for ketones in your urine if your blood sugar stays above 250 mg/dL for several hours, even if you’ve taken insulin.

Recognizing the signs of both high and low blood sugars can help you and your loved ones keep their levels within a healthy range and help prevent the onset of a diabetic coma.

It is important to connect with your doctor regularly to make sure that you’re calibrating your medications as needed. Some other tips to make sure you’re staying on top of your diabetes management include:

  • Double-check your insulin doses before injecting.
  • Eat all of the carbohydrates that you’ve dosed for.
  • Check the expiration dates on all of your insulin and other diabetes medications.
  • Eat regular meals.
  • Have low snacks with you at all times.
  • Wear a diabetes ID bracelet.
  • Take your insulin and other diabetes medications as prescribed.
  • Treat both lows and highs often and early.

Diabetic comas can be scary and life threatening, but it is within your power to help prevent them and stay healthy.