Hypoglycemia: Overview

Alternative names: Low blood sugar, Absolute hypoglycemia, Fasting hypoglycemia, Reactive hypoglycemia, Postprandial hypoglycemia

Hypoglycemia is a common condition in which blood sugar levels fall below normal levels.  Most often a side-effect of diabetes medication, symptoms range in severity from clumsiness and confusion... to death.

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Sugar levels frequently change throughout the day and may be normal sometimes and abnormal at others.

Young man sleeping on sofa after a large meal
Falling asleep after a meal (a "food coma") is quite normal and doesn't necessarily mean you have hypoglycemia.

Fasting hypoglycemia (also known as absolute hypoglycemia) is the most common type and can occur after a long period without food, or after strenuous exercise.

Reactive hypoglycemia (also called postprandial hypoglycemia) occurs after meals.  However, just because a person becomes tired after eating doesn't mean there is a problem: in general, a little bit of sleepiness after eating is completely normal and nothing to worry about.

Causes and Development; Contributing Risk Factors

Fasting hypoglycemia can be caused by:

Reactive hypoglycemia refers to low blood sugar that occurs within 4 hours of eating a meal.  It can be caused by:

  • High sugar / refined carbohydrate intake leading to hyperinsulinism (overproduction of insulin)
  • Deficiency of hormones that regulate glucose production as caused by, for example, hypothyroidism or adrenal insufficiency
  • Congenital enzyme deficiencies such as hereditary fructose intolerance
  • Alimentary or gastric surgery leading to rapid stomach emptying or "dumping syndrome" in about 15% of cases.

Two factors can lead to sugar overload: An overconsumption of sugar and a problem with sugar metabolism.  Over-consumption of sugar begins at an early age – just check out the sugar levels in the most popular children's cereals.  You will find that many contain almost 50% of their calories as sugar.  Sugar is addictive, and difficult to avoid because it is added to almost every packaged food sold today.

Hypoglycemia is uncommon in those without diabetes.  Additional risk factors include:

  • pregnancy
  • a weakened immune system
  • poor diet, high in refined carbohydrates
  • prolonged use of some pharmaceutical drugs such as antibiotics or beta-blockers
  • chronic stress, either physical or mental
  • irregular heartbeat (arrhythmia)
  • allergies
  • breast cancer
  • upper gastrointestinal tract surgery

Signs and Symptoms

Hypoglycemia is a general term used to describe a mixed bag of symptoms that are due to a derangement of glucose metabolism.  Under the strict medical definition, hypoglycemia mainly refers to a drop in fasting blood sugar below 50mg% (normal range 70-90mg%).  This drop can be associated with differing symptoms depending on the rate at which the blood sugar falls.

Symptoms typically appear quickly and include clumsiness, confusion, difficulty speaking, weakness, shakiness, excess hunger, anxiety, outbursts, faintness, headaches, passing out, delirium, coma, hallucinations, excess sweating, the appearance of intoxication, seizures, marked personality changes, irritability, negativism, mood swings, depression, crying spells, and various similar mental symptoms.

Diagnosis and Tests

Tabular and graphical results of a 2-hour glucose tolerance test
Results from a 2-hour Glucose Tolerance Test (GTT) showing minimum-maximum range in red and actual readings in blue.

A Glucose Tolerance Test (ideally lasting 5-6 hours) can confirm a diagnosis, but more alternative doctors are forgoing the inconvenience and shock to the system because symptoms alone are reliable enough.  Central nervous system changes, adrenal hormone output and detoxification (what the body tries to do when it is not busy digesting food) also contribute to the overall symptom picture.

There are different interpretations given to different patterns seen on glucose tolerance testing.  One such system describes three types of curves:

Type 1 (Neuroglycopenic)
This type results in a rapid rise in blood glucose within the first hour followed by a pronounced or precipitous drop in blood glucose in the second hour.  Symptoms of this type of response are rapid mood swings, volatile personality, erratic behavior before and after eating.  Possible cause of this response is gastric dumping, too large an insulin response (pancreatic problems) and glucose tolerance factor problems (liver problems).

Type 2 (Adrenergic Type)
After ingestion of glucose the blood sugar rises for the first three hours followed by a hypoglycemic rebound at 4 to 6 hours.  Symptoms associated with this type of response are tiredness 2 hours after eating, allergic responses or food intolerances, and shakiness before meals.  When blood sugar falls rapidly, the early symptoms are those brought on by a compensating secretion of adrenalin; these include sweating, weakness, hunger, racing pulse and an "inner trembling".  This response can be due to adrenal cortical insufficiency or thyroid deficiency.

Type 3 (The Flat Curve Response)
In this case the blood glucose does not deviate more than +/- 15% from fasting level through the whole test.  Symptoms that may appear are fatigue, apathy or hypotonia (poor muscle tone).  These symptoms are due to poor digestion and absorption of nutrients.

Treatment and Prevention

The term "hypoglycemia" may be better named "carbohydrate intolerance syndrome" and treated accordingly.


Patients with hypoglycemia of varying causes appear to show similar personality patterns, suggesting hypoglycemia can cause personality disorders.

Signs, symptoms & indicators of Hypoglycemia:

Symptoms - Cardiovascular

Symptoms - Food - General

(Very) strong appetite

Hunger is a symptom of hypoglycemia.


Symptoms - Food - Preferences

Symptoms - General

Symptoms - Head - Eyes/Ocular

(Severe) vision disturbances

Blurred vision and diplopia (double-vision) are possible symptoms.

Symptoms - Head - Mouth/Oral

Symptoms - Metabolic

Adverse reaction to delayed meals

Skipping a meal causes blood sugar levels to drop, triggering a release of hormones that compensate for low glucose levels.  These can narrow the arteries, increase blood pressure, and result in headaches or migraines.  Low blood sugar also leads to fatigue and the feeling of weakness.

Symptoms - Mind - Emotional

Very angry/hostile disposition

Uncontrolled rage is a possible symptom.

Symptoms - Mind - General

Symptoms - Muscular

Symptoms - Nervous

Symptoms - Reproductive - Female Cycle

Symptoms - Sleep

Regular/frequent bizarre dreams

When the brain senses low glucose levels, it will employ various mechanisms to try and rectify the situation.  One way is by releasing adrenaline, which can cause vivid dreams that are accompanied by a feeling of being "wired" (nervous, tense, on edge, highly stimulated).

Conditions that suggest Hypoglycemia:


Addictions / Addictive Tendencies

A craving for cigarettes and/or drugs is a possible symptom of hypoglycemia.



Low DHEA Level

Insulin levels may play a significant role in determining how much DHEA is metabolized.  Studies have discovered that low levels of DHEA may be related to an excess of insulin.  What this suggests is that anyone suffering from hypoglycemia or excess insulin may be prone to converting nutrients to fat due to depressed DHEA levels.



Dizziness and fainting spells are a possible symptoms of hypoglycemia, which may in turn be a reaction to insulin.


Muscle Cramps / Twitching

As hypoglycemia progresses a variety of symptoms can occur including muscle twitching.  Amongst 300 patients in one study (185 female, 115 male) found to have relative hypoglycemia (a drop of 20% or more below the fasting blood sugar level during a 6-hour glucose tolerance test), 23% had muscular twitching or cramps.

Nervous System


Early symptoms of hypoglycemia, such as hand tremors, are similar to those which occur as the result of experiencing a sudden and violent fear.



Restless Leg Syndrome

Based on afternoon glucose tolerance testing, many patients with RLS – particularly if they also have spontaneous leg cramps – appear to have hyperinsulinism causing functional 'hypoglycemia' during testing.  In fact, some patients may have an attack of muscle cramps at the same time as their lowest level of plasma glucose.  In an open trial, a group of 350 patients with this type of glucose tolerance curve were placed on a sugar-free, high protein diet along with frequent nibbling and at least one night feeding.  The vast majority experienced a prompt remission or, at least, a striking reduction in symptoms. [J Med Assoc 60(5): pp.29-31, 1973]

Symptoms - Glandular

Risk factors for Hypoglycemia:

Environment / Toxicity

Heavy Metal Toxicity

Heavy metals such as mercury, cadmium, lead and thallium poison the glucose metabolizing catalysts, thus reducing the flow of energy throughout the body.  It is interesting to note that the symptoms of heavy metal poisoning are similar to symptoms associated with hypoglycemia i.e. hyperactivity, mood swings, manic depressive behavior, poor concentration and impulsive and unpredictable behavior.

Mercury Toxicity (Amalgam Illness)

Heavy metals such as mercury, cadmium, lead and thallium poison the glucose metabolizing catalysts, thus reducing the flow of energy throughout the body.  It is interesting to note that the symptoms of heavy metal poisoning are similar to symptoms associated with hypoglycemia i.e. hyperactivity, mood swings, manic depressive behavior, poor concentration and impulsive and unpredictable behavior.



Patients suffering with Wilson's Syndrome, a form of hypothyroidism, occasionally experience intense and previously unfamiliar cravings for sweets.  The low body temperature patterns may affect the function of enzymes involved in glucose metabolism that could result in lower blood sugar levels which might contribute to sweet cravings.

Symptoms - Food - Intake

Symptoms - Head - Ears

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Hypoglycemia suggests the following may be present:


Hypoglycemia can lead to:



Endogenous depression – depression originating from within as opposed to being due to external factors – is a known symptom.

Poor Memory

Temporary forgetfulness is a known symptom of hypoglycemia.



Night Sweats

Nighttime hypoglycemia may be without symptoms or manifest itself as night sweats, unpleasant dreams or early morning headache.

Hypoglycemia could instead be:



Numerous patients given psychiatric diagnoses have actually turned out to have hypoglycemia, including those classified with depression, manic-depressive disorder, and schizophrenia.

Recommendations for Hypoglycemia:


Book Reading

For additional reading from a sufferer's perspective, you could read the book The Low Blood Sugar Handbook: You Don't Have to Suffer... by Edward A. Krimmel, Patricia T. Krimmel.  It is not a dry technical book, but one that you should enjoy while helping you resolve the problem.

Botanical / Herbal


If you must use sweeteners, stevia is an excellent natural alternative to simple sugars and unhealthy chemical alternatives.


Sugar Avoidance / Reduction

Consuming foods that contain simple sugars makes the problem worse.  Avoid sweets other than fresh fruits, if tolerated.  In addition, consider avoiding products that only "taste" sweet (artificially sweetened – low calorie).  Even though they may contain no sugar, sending signals to your brain that something "sweet" is being consumed may have negative consequences.

Processed Foods Avoidance

Refined carbohydrates are more readily absorbed than unrefined, and should be avoided in those with any glucose intolerance.

Smaller, More Frequent Meals

Frequent small meals are more effective in stabilizing blood sugar levels than large, less frequent ones.  Remember to consume something before symptoms appear.  Protein snacks that keep well should be stored in locations such that you always have quick access to food.  You may find it helpful to store protein bars or nuts in your car, at work, in your pockets or (for women) in your purse.

High/Increased Protein Diet

A diet consisting of higher protein and fat with less refined carbohydrates is a standard recommendation for those with hypoglycemia.

Caffeine/Coffee Avoidance

Avoid all soft drinks, coffee, tea, artificial colors and additives.

Alcohol Avoidance

Drinking alcohol can cause blood sugar to drop in some sensitive individuals.  Hypoglycemia has been well documented in chronic alcoholics and binge drinkers.

High/Increased Fiber Diet

Soluble fiber delays gastric emptying, slows glucose absorption, and minimizes blood glucose swings.

Therapeutic Fasting

In severe cases, additional methods of support besides diet may be needed and perhaps the best of these is fasting.  Fasting is a useful, inexpensive and universally available treatment for hypoglycemia.  The fast allows the entire system to restore its cellular integrity.

Increased Fruit/Vegetable Consumption

Fruit contains several things that are of benefit, including a sugar (fructose) that does not cause wild glucose swings, trace minerals, and fiber which slows glucose absorption.


Aerobic Exercise

Moderate exercise improves glucose metabolism.  Those few individuals who find that strenuous or prolonged exercise causes hypoglycemia should take food at the earliest opportunity.

Laboratory Testing

Glucose Tolerance Test

The six hour oral glucose tolerance test is normally used to determine the type and magnitude of the glucose intolerance.



Chromium status should be optimized for its benefit in carbohydrate disorders (both hypoglycemia and adult-onset diabetes).


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