Hypoglycemia, also called low blood sugar, occurs when your blood glucose (blood sugar) level drops too low to provide enough energy for your body's activities. In adults or children older than 10 years, hypoglycemia is uncommon except as a side effect of diabetes treatment, but it can result from other medications or diseases, hormone or enzyme deficiencies, or tumors.
Glucose, a form of sugar, is an important fuel for your body. Carbohydrates are the main dietary sources of glucose. Rice, potatoes, bread, tortillas, cereal, milk, fruit, and sweets are all carbohydrate-rich foods.
After a meal, glucose molecules are absorbed into your bloodstream and carried to the cells, where they are used for energy. Insulin, a hormone produced by your pancreas, helps glucose enter cells. If you take in more glucose than your body needs at the time, your body stores the extra glucose in your liver and muscles in a form called glycogen. Your body can use the stored glucose whenever it is needed for energy between meals. Extra glucose can also be converted to fat and stored in fat cells.
When blood glucose begins to fall, glucagon, another hormone produced by the pancreas, signals the liver to break down glycogen and release glucose, causing blood glucose levels to rise toward a normal level. If you have diabetes, this glucagon response to hypoglycemia may be impaired, making it harder for your glucose levels to return to the normal range.

Symptoms
Symptoms of hypoglycemia include
hunger
nervousness and shakiness
perspiration
dizziness or light-headedness
sleepiness
confusion
difficulty speaking
feeling anxious or weak
Hypoglycemia can also happen while you are sleeping. You might
cry out or have nightmares
find that your pajamas or sheets are damp from perspiration
feel tired, irritable, or confused when you wake up
Content Courtesy : diabetes.niddk.nih.gov
^{Note : Information herein is provided for informational purposes only and is not a substitute for professional medical advice. You should not use this information for diagnosing or treating a medical or health condition. If you have or suspect you have a medical problem, promptly contact your professional healthcare provider. Please consult your healthcare provider before beginning any course of supplementation or treatment.}