Glucose, which is also referred to as blood sugar, provides the body with its main energy source. When you eat carbohydrates, a variety of digestive enzymes and secretions break them down into simple sugars, including glucose. The body uses some available glucose while converting excess amounts to glycogen and storing it in the liver as a backup energy source. There are a variety of organs and hormones involved in the regulation of normal glucose levels in the blood.
Physiology
As glucose enters the bloodstream after a meal, the pancreas releases the hormone insulin. Insulin binds to glucose and helps the body use it for energy. When the body uses up the glucose in the bloodstream, levels of glucose in the blood drop. When blood glucose levels drop, the pancreas releases a different hormone, called glucagon, to stimulate the breakdown of glycogen into glucose. Once glycogen is broken down, the liver releases it into the blood in an effort to provide the body with energy.
Insulin Resistance
Insulin resistance occurs when the pancreas properly produces and releases insulin, but the body is not able to use it efficiently. The cells of the muscles, fat and liver become resistant to insulin and, as a result, the pancreas produces excess amounts, according to The National Diabetes Information Clearinghouse. Eventually, the pancreas stops its insulin production and glucose levels in the blood rise. Insulin resistance usually affects those who are overweight or sedentary. The National Diabetes Information Clearinghouse also notes that there may be a genetic factor in insulin resistance.
Pre-Diabetes
In many cases, insulin resistance leads to a condition called pre-diabetes, or impaired fasting glucose. Pre-diabetes is characterized by glucose levels that are higher than normal, but not high enough to be diagnosed as diabetes. A blood sugar level of 100 to 125 mg/dL of blood usually warrants a pre-diabetes diagnosis. Insulin resistance and pre-diabetes do not usually cause any symptoms.
Hypoglycemia
Hypoglycemia occurs when blood glucose levels drop below normal. Hypoglycemia often affects diabetics who have not followed their eating plan. It can also occur after an extended period of fasting or as a result of other health conditions, such as tumors on the pancreas, certain medications, alcohol or hormonal deficiencies, according to MayoClinic.com.
Symptoms of Hypoglycemia
When glucose levels fall too low, it can adversely affect brain function. This causes a variety of neurological symptoms, including confusion, abnormal behavior, double vision and blurred vision. Other symptoms that may occur include tremor, anxiety, increased perspiration, hunger and heart palpitations. In rare, extreme circumstances, hypoglycemia can lead to loss of consciousness or coma.
