Blood glucose, also referred to as blood sugar, is the body's main source of energy. Glucose enters the body mainly through the consumption of carbohydrates. Each type of carbohydrate has different effects on blood glucose levels depending on how fast it moves through the bloodstream. According to MedlinePlus, normal fasting blood glucose levels are around 100 mg/dL. Hypoglycemia occurs when blood glucose levels fall too low.
Physiology
After you eat carbohydrates, they move through the digestive tract where they are broken down into the sugar glucose. Glucose moves from the digestive tract into the bloodstream, where it triggers the release of insulin from the pancreas. Insulin helps the cells use glucose for energy, thus lowering the levels of glucose in the blood. If an excess of glucose enters the body, some of it will be stored in the liver and muscles as glycogen. These glycogen stores act as your body's source of energy between meals and are meant to keep blood sugar levels from falling too low.
Causes
In some people, insulin responses or glycogen storage is impaired. This leads to disruptions in the body's physiological processes, which can lead to hypoglycemia. There are various conditions that cause this disruption, including hypopituitarism, hypothyroidism and a long period of fasting. In diabetics, hypoglycemia can be caused by taking too much insulin at one time. In rare circumstances, a tumor on the pancreas, called an insulinoma, can trigger the release of excess insulin.
Types
Hypoglycemia is broken down into two subgroups--fasting hypoglycemia and reactive hypoglycemia, according to the National Diabetes Information Clearinghouse. Fasting hypoglycemia, also referred to postabsorptive hypoglycemia, is usually a result of an underlying disease. Reactive hypoglycemia, or postprandial hypoglycemia, occurs within 4 hours of eating a meal. Both forms of hypoglycemia produce the same symptoms.
Symptoms
Mild drops in blood glucose do not usually produce any symptoms. When blood glucose levels become too low, it can affect the brain, causing confusion, abnormal behavior, double vision and blurred vision. MayoClinic.com notes that seizures and loss of consciousness may also occur, although these symptoms are rare. In addition to neurological symptoms, hypoglycemia can also cause heart palpitations, tremors, increased sweating, anxiety and increased hunger.
Treatment
Initial treatment for hypoglycemia focuses on restoring blood glucose levels. This can be done through the ingestion of glucose tablets or any food or beverage that is a rich source of simple carbohydrates, such as candy, fruit juice or regular soda. According to the National Diabetes Information Clearinghouse, the goal is to consume 15 g of carbohydrates immediately. Once blood glucose levels are restored, further treatment will focus on the specific cause of the hypoglycemia.
