What is ketotic hypoglycemia?

A quick and easy-to-read introduction

In a normal person, fuel for the brain and the general cell metabolism primarily comes from the burning of sugar deposits (glycogen).

When the glycogen stores are depleted, the body will switch to burn fat deposits. The fat burn lead to two fuels for the brain, both glucose (sugar) and ketone bodies.

However, ketones in the blood will lead to nausea and eventually vomiting.

This will lead to a vicious circle, where you cannot eat or drink sugar-rich items, which again leads to further fat burn and production of ketone bodies.

We will go into greater detail about ketotic hypoglycemia here, but first – a brief summary if you’re short on time.

The 1-minute explanation

Ketotic hypoglycemia is a condition characterized by low blood sugar (glucose) and elevated ketones, typically occurring after fasting, like sleeping overnight. Ketotic hypoglycemia (KH) is not a disease itself but rather a symptom or a clinical presentation that can occur as a result of various underlying conditions.

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What is Ketotic Hypoglycemia – Video

Before we move on with the rest of the explanation, we understand that some may learn better through video than text. That’s perfectly okay.

If that’s you, we have a thorough guide on what Ketotic Hypoglycemia is, presented by Dr. David Weinstein.


Ketotic Hypoglycemia – In Detail

Now that we have the basics covered, we have provided two seperate angles from which you can view this. 

For the patients

In a KH-patient, the glycogen stores are somehow insufficient. This leads to decreased fasting tolerance with earlier onset of fat burn and hence ketone bodies.

In most patients, the hypoglycemia is relatively mild, and the ketone bodies help to provide fuel to the brain, which prevents loss of consciousness and convulsions.

However, in relatively few patients, the condition is more severe, but still without an identified cause despite intense investigations in hormones and cell metabolism.

Such patients are said to have “idiopathic” KH, or IKH, which simply means KH without any known cause. 

For the doctors

Ketotic hypoglycemia can be seen in children because of growth hormone deficiency, cortisol deficiency, metabolic diseases with intact fatty acid consumption, including glycogen storage diseases (glycogenosis; GSD) type 0, III, VI, and IX, or disturbances in transport or metabolism of ketone bodies.

When these diagnoses are excluded, ketotic hypoglycemia can be categorized as unexplained or idiopathic (IKH), otherwise known as accelerated starvation.

The primary treatment is dietary prevention with long carbohydrates (e.g. uncooked cornstarch) and frequent meals. In some more severely affected patients, continuous feeding may be needed through a gastrostomy tube.

Emergency treatment constitutes of oral or i.v. glucose, eventually i.m. glucagon, to raise the plasma glucose, which will prevent further lipolysis.

However, the ketones can take hours to be eliminated. In more severely affected patients, the ketone production can be significant before hypoglycemia occurs, why recognition of increased ketones above approximately 1.5 mol/L is important, sometimes already when the glucose concentration goes below 3.9 mmol/L (70 mg/ dL).

Pathological vs. physiological KH

A recent paper published by families of Ketotic Hypoglycemia International and the medical experts in the Scientific Advisory Board has for the first time differentiated between a pathological form of ketotic hypoglycemia and a physiological form; 

1. Physiological

This is a normal response to prolonged fasting or illness and is more common. It’s typically less severe.

Sometimes a child with pathological KH will present with their first episode during prolonged illness, so the severity (how low the glucose, and how high the ketones were) should always be taken into consideration when considering a child presenting with illness and KH.

Most medical experts agrees that seizures accompanied by a blood glucose below 40 should always prompt further investigations. 

2. Pathological

This is a much rarer and more severe form. It requires specialized care and support. This is the more concerning form of IKH.

It is characterized by recurrent symptomatic episodes accompanied by specific biochemical markers. These episodes involve ketone levels of ≥ 1.0 mmol/L and blood glucose levels below 70 mg/dL (3.9 mmol/L).

Importantly, these episodes occur in the absence of prolonged fasting, acute infections, and chronic diseases known to cause ketosis.

Pathological IKH may be indicative of underlying, undiscovered diseases, why often extensive investigations are required before labeling the patient as “idiopathic” (meaning: unknown cause). 

While the pathological form may be caused by undiscovered diseases, the medical communities around the world are now increasingly paying attention to the patients suffering from pathological ketotic hypoglycemia with no known cause.

These patients are now often referred to as having; pathological idiopathic ketotic hypoglycemia, or to say it in plain language: Low blood glucose with high ketones, with no known cause. 

Finding support

Entering the diagnostic process for ketotic hypoglycemia (IKH) can be an overwhelming experience for parents. 

It’s common for families to join our patient community with a sense of fear and uncertainty, often stemming from their child’s admission to the hospital where the term “ketotic hypoglycemia” was first introduced. 

Questions naturally arise: Is this a chronic and dangerous condition?

The reassuring answer is that, in most cases, it is not. 

Even if your child is diagnosed with the pathological form of IKH, we want to assure you that support is readily available within our community.

Many of our families, even those coping with the challenges of pathological IKH, are leading fulfilling lives. 

They have learned to navigate the ups and downs of the IKH rollercoaster, and their experiences can provide valuable insights and support as you embark on this journey. 

You are not alone, and together, we can face the uncertainties and complexities of IKH with resilience and unity. 

Currently, we have united 2,000 families from all over the world on our Facebook Support Group. Join us!