Hypoglycemia

Hypoglycemia is when the level of blood sugar is lower than normal. A normal blood sugar level is about 70 to 100 milligrams per deciliter. All of the cells in the body need sugar to do their jobs and to survive. When a person does not have enough blood sugar, their body cannot work normally.
Hypoglycemia can cause many symptoms. Some common symptoms are nausea, feeling hungry, sweating, feeling sad, and heart palpitations (feeling the heart pounding). Bad hypoglycemia can make a person act like they are drunk or have taken drugs. Very bad hypoglycemia can look like a stroke. 
Hypoglycemia can happen to anyone, at any age, but it usually happens in people who are diabetic. It is often a complication of treatment for diabetes with insulin or oral medications. 
Hypoglycemia is treated by returning the blood sugar levels back to normal. Often, a hypoglycemic person can bring their blood sugar levels back up by eating. In the worst cases, when the blood sugar is very low, hypoglycemia is treated by giving sugar water intravenously (through a needle placed into a vein). In some cases, the liver is able to handle the issue by making glucose.
The brain and other parts of the body cannot work without sugar. Because of this, severe (very bad) hypoglycemia can cause serious medical problems (like seizures) or even death if it is not treated quickly enough.