Test Glucose Tolerance

The test requires that the patient fast overnight, and then consume 75 to 100gm of glucose in water.

The Diabetic test is a 2 hour G.T.T. with just 3 readings, the fasting, the 1 hour and the 2 hour. This test is not correct for testing Functional or Reactive Hypoglycemia. With Hypoglycemia one is interested in the full reactions to a sugar load. In both cases a 75to 100gm load of glucose is given to the patient after having collected blood for the fasting level. With Reactive Hypoglycemia the emphasis in on the word “Reactive”- one is looking for the sugar reactive phenomenon in which the blood sugar either drops suddenly or falls very low. The test should be conducted over a longer period of time than with the diabetic test (3,4,5 hours or longer with blood samples taken at these times or whenever symptoms present). Part of diagnostic criteria for Hypoglycemia is the rate of fall of blood sugars, hence the relationship between consecutive readings is very important. Sudden drops in blood glucose will usually trigger an adrenaline response and subsequently adrenaline symptoms such as nervousness, shakiness, dry mouth, irritability, agitation, neck stiffness and sometimes palpitations or a racy heart.

With Reactive Hypoglycemia one is also seeking to ascertain how low the blood sugar may go as this in fact is one of the measures of severity. The brain is dependent on blood glucose as it’s only fuel supply under normal circumstances. When the blood glucose falls below a certain level, usually 3.6mm/L, there is a lack of available fuel to the brain and symptoms of brain starvation will occur – these include tiredness, moodiness, depression, forgetfulness, poor concentration and cloudy headedness.


Test Glucose Tolerance can help with the following



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


Highly recommended



(gm): A metric unit of weight, there being approximately 28 grams in one ounce.


A sugar that is the simplest form of carbohydrate. It is commonly referred to as blood sugar. The body breaks down carbohydrates in foods into glucose, which serves as the primary fuel for the muscles and the brain.

Diabetes Mellitus

A disease with increased blood glucose levels due to lack or ineffectiveness of insulin. Diabetes is found in two forms; insulin-dependent diabetes (juvenile-onset) and non-insulin-dependent (adult-onset). Symptoms include increased thirst; increased urination; weight loss in spite of increased appetite; fatigue; nausea; vomiting; frequent infections including bladder, vaginal, and skin; blurred vision; impotence in men; bad breath; cessation of menses; diminished skin fullness. Other symptoms include bleeding gums; ear noise/buzzing; diarrhea; depression; confusion.


A condition characterized by an abnormally low blood glucose level. Severe hypoglycemia is rare and dangerous. It can be caused by medications such as insulin (diabetics are prone to hypoglycemia), severe physical exhaustion, and some illnesses.


(mm): A metric unit of length equaling one thousandth of a meter, or one tenth of a centimeter. There are 25.4 millimeters in one inch.

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