Glucose is a simple sugar, a building block of complex carbohydrates and a common source of energy for all living things. Without glucose, the human body would shut down, deprived of the fuel it needs to power its most basic functions. Too much glucose, however, can lead to illness and major health problems.
Sources
Humans get their glucose from the food they eat. The primary source of glucose is carbohydrates, which may consist of chains of glucose molecules, or they may also include other sugars like fructose and sucrose. The digestive system breaks these carbohydrates down and releases glucose into the blood, where it can fuel the body. Faced with a lack of carbohydrates, the body can convert fats and proteins into glucose for fuel as well.
Utilization
When glucose enters the bloodstream, some of it flows directly to the brain and other organs where it serves as fuel. Excess glucose in the bloodstream triggers the insulin response, which stores the glucose in fat, muscles and the liver. The body can then use it during periods of low blood glucose to provide a consistent fuel source.
Insulin
Insulin is the hormone that regulates glucose in the blood. According to the American Diabetes Association, under normal circumstances insulin maintains glucose at under 100 mg per dL. In the case of type 1 diabetes, the pancreas does not produce enough insulin to maintain proper management of blood sugar, causing an excess of glucose to remain in the bloodstream. Type 2 diabetes, also known as adult-onset diabetes, comes from exposing the body to an excess of sugars over a long period. Eventually, the body begins to develop a resistance to insulin's effects, causing a similar increase in blood glucose despite the presence of insulin.
Hyperglycemia
If the body's ability to utilize and store glucose fails, sugar remains in the bloodstream instead of being stored properly. This can lead to a dangerous condition called hyperglycemia. The increased level of sugar in the blood can cause damage to major organs, especially the heart and eyes, and reduce the body's resistance to opportunistic infection. In extremely high concentrations, it can even lead to coma and death.
Hypoglycemia
Hypoglycemia is a lack of glucose in the blood, and it can lead to a host of symptoms and problems. Dizziness, lightheadedness, sweating and shaking are all common symptoms of low blood sugar, and in extreme cases, neurological symptoms and even coma can result from a lack of glucose. Luckily, low blood sugar is relatively easy to treat; consuming carbohydrates can quickly return a sufferer to normal.
