Sugar in the bloodstream, known as blood glucose, is the body's main source of energy, and carbohydrates are the main source of blood glucose. As blood glucose levels rise, such as after eating a meal, the pancreas secretes a hormone called insulin that allows the body to process the glucose. In a healthy person, the pancreas secretes just enough insulin to compensate for the level of sugar in the blood, but certain lifestyle factors or medical conditions can throw blood glucose levels out of balance.
Blood Glucose Levels in Adults
The National Institute of Health's Medline Plus puts normal blood glucose levels for adults at 70 mg/dl to 130 mg/dl. Blood glucose levels rise naturally after consuming carbohydrates, and a non-diabetic person can expect to see blood glucose levels of up to 180 mg/dl after eating a meal. A fasting blood glucose test involves abstaining from all food and drink consumption for eight hours before having blood drawn. Blood glucose levels in a healthy person after a fasting blood glucose test should be less than 100 mg/dl. Levels between 100 mg/dl and 125 mg/dl indicate that there may be a medical issue, such as prediabetes, while levels higher than 125 mg/dl are usually an indication of diabetes.
Blood Glucose Levels in Children
Because children are constantly growing and developing, their energy needs are different from adults. The Juvenile Diabetes Research Foundation gives an average range of 75 mg/dl to 165 mg/dl for children, although the number will differ by age. In fact, children under the age of 5 may have normal blood glucose levels of 100 mg/dl to 200 mg/dl, while children from 5 to 11 years old may normally have levels of 70 mg/dl to 180 mg/dl.
Hyperglycemia
Hyperglycemia is a condition in which blood glucose levels rise higher than normal. Diabetes, insulin resistance or pancreatitis are common causes, but strenuous physical exercise or severe illness can cause bouts of transient hyperglycemia. Prolonged hyperglycemia can have devastating effects on the body, damaging the nerves, heart, eyes and kidneys.
Hypoglycemia
When blood glucose levels dip below 70 mg/dl, a condition called hypoglycemia can set in. Hypoglycemia can become a medical emergency fairly quickly, leading to seizures, coma and even death. While people suffering from diabetes and other conditions, like hyperinsulinism, are at greater risk for hypoglycemia, excessive alcohol consumption, lack of food, stress and liver diseases can also cause blood glucose levels to dip.
