There are several important conditions that may predispose a person to develop hypoglycemia or abnormally low blood sugar. The risk of hypoglycemia developing also depends on several other factors such as a person's age, their physical activity level and their lifestyle habits.

Causes

Hypoglycemia may arise for a variety of reasons in various different age groups and some examples include:

Hypoglycemia in newborn babies

Newborn babies can develop hypoglycemia for several reasons. Babies born prematurely or with complications at birth such as intrauterine growth retardation or breathing difficulties are at an increased risk of developing hypoglycemia.

Babies born to mothers who developed diabetes during pregnancy (gestational diabetes) are also more likely to develop hypoglycaemia after birth. Disorders such as hyperinsulinism (high levels of blood insulin), an underactive pituitary gland and various inborn errors of metabolism can also lead to hypoglycemia in newborns. Other risk factors include prolonged exposure to cold temperatures causing hypothermia, sepsis, starvation and infection.

Hypoglycemia in children

Hypoglycemia may arise in children for a variety of reasons, some of which include malnutrition, infective diarrhea and vomiting, hyperinsulinism, and hypopituitarism. Other causes include prolonged periods without food, type 1 diabetes, and a number of inborn errors of metabolism.

Children may also develop hypoglycemia due to accidental poisoning or ingestion of blood sugar lowering drugs such as the sulphonylureas.

Hypoglycemia in adolescents and young adults

Hypoglycemia most commonly arises in this age group as a complication of type 1 diabetes. Individuals may have taken too much insulin, over exerted themselves, consumed an excessive amount of alcohol, eaten a meal too late or missed a meal altogether. Other causes include type 2 diabetes, ketotic coma, insulin-secreting pancreatic tumor, major blood infection (sepsis) and Addison's disease.

Hypoglycemia in adults

Hypoglycemia commonly arises in this age group as a complication of diabetes mellitus, especially if the condition is being managed with insulin or another blood sugar lowering regimen. Taking too much of the medication, exercising vigorously, or drinking too much alcohol can increase the likelihood of blood sugar levels dropping and leading to symptoms of hypoglycemia.

Hypoglycemia in the absence of diabetes

There are two types of hypoglycemia that can occur in people without diabetes and these include postprandial hypoglycemia which describes a reactive hypoglycemia that occurs within 4 or 5 hours of eating and fasting hypoglycemia or post absorptive hypoglycemia which can be an indicator of a serious health condition.

Some medications such as quinine, salicylates and propranolol can also reduce blood sugar and cause hypoglycaemia.