Causes of Low Blood Sugar
Hypoglycemia is defined as a deficiency of glucose, or blood sugar, in the bloodstream. Glucose is used by the body as a source of energy. When blood glucose levels fall, the pancreas signals the liver to release stored, excess glucose to raise sugar levels. The onset of low blood sugar, and what is supposed to be an automatic regulatory response to this deficiency, can be impaired by diabetes; non-diabetic conditions of the liver, pancreas, adrenal or pituitary glands; or the ingestion of too much alcohol.
People with diabetes take insulin, a pancreatic hormone, to lower dangerously high blood sugar levels and keep them regulated. If the amount of insulin injected into the bloodstream is too high, in proportion to the amount of glucose in the diabetics’ bloodstream, blood sugar levels can drop below normal, healthy levels.
Another problem for diabetics regarding low blood sugar is not eating enough food to produce a sufficient level of glucose after taking diabetes medication. Using too much glucose through strenuous exercise, after taking diabetes medication can also cause low blood sugar readings.
Non-Diabetic Illnesses and Disorders
The extended periods of starvation that occur for those suffering from anorexia nervosa can result in the body’s inability to produce sufficient blood sugar. Severe hepatitis, a disease which causes inflammation of the liver, can also cause blood sugar levels to drop to healthy levels.
Tumors can also cause low blood sugar levels, in contrasting ways. Tumors that become too large can use too much of the glucose present in the bloodstream, or–in the case of a rare pancreatic tumor known as insulinoma–a tumor can cause an overproduction of insulin that causes blood sugar levels to drop.
Other potential non-diabetic illnesses which can cause low blood sugar are disorders of the adrenal or pituitary gland, which can create a shortage of the hormones necessary to control and maintain glucose production.
Food and Alcohol Related Causes
Drops in blood sugar levels caused by food and/or alcohol intake (or lack thereof) are the most easily controllable and reversible. Temporary drops in blood sugar levels can occur after excessive drinking of alcohol, particularly when the drinking has taken place on an empty stomach. In this situation, the alcohol present in the bloodstream prevents the liver from releasing necessary levels of glucose into the blood.
People who fast for periods of time, either for religious or health-related reasons, can experience temporary blood sugar level reductions due to under-nourishment. The opposite situation is the case for those with reactive or postprandial hypoglycemia, in which eating causes the individual to produce an excess of insulin in reaction to the ingestion of the food.