While deficiency of insulin, resulting in diabetes mellitus, is far more serious and more common than excessive action of the pancreas, cases do occur in which there is too much insulin, with a resulting low blood sugar. The sugar level of the blood is maintained by the body’s use of glucose in the muscle, liver, brain, and other organs, and by the way in which the glucose is brought back into the blood from the liver and the muscles, and the secretion of insulin, which makes possible the use of sugars by the body.
Following meals or periods of excitement there may be excess sugar in the blood, so that the body puts out extra insulin tending then to lower the sugar below normal. In other instances there may be low blood sugar because of a deficiency of the liver in storing sugar. Other cases are known in which tumors affecting the cells of the pancreas may produce excess insulin and with that a low blood sugar.
Overactivity of the nervous system can cause excessive flow of insulin into the blood. In all of these conditions the blood sugar becomes low; as a result, there is weakness and faintness, a rapid heart, anxiety and palpitation. When the person takes sugar or carbohydrates the symptoms are relieved.
In general, people who have low blood sugar do well on diets that are high in protein and fats and low in sugar. When a high sugar diet is taken, the body reacts by putting out excessive insulin, which tends to lower the sugar below normal. Excessive secretion of insulin can be controlled by the taking of certain drugs such as derivatives of belladonna and atropine, but control of the emotional and dietary factors is considered a more satisfactory method of treating the condition.