The basic defect in all patients with diabetes is the decreased ability of insulin to induce cells of the body to remove glucose (sugar) molecules from the blood. Whether this decreased insulin activity is due to a decreased amount of insulin produced (type 1 diabetes), or from the insensitivity of the cells to a normal amount of insulin (type 2 diabetes), the results are the same: blood glucose levels which are too high. This is termed "hyperglycemia" which means "high glucose in the blood."
hyper = high, glyc = glucose, and emia = of the blood.
The Classic Symptoms
Other Symptoms Might Include
It is important to remember that not everyone with diabetes will have all these symptoms. In fact, many people with type 2 diabetes may not have any of them.
The classic symptom of being hungry frequently stems from the fact that a person with diabetes cannot utilize glucose well as an energy source within cells. The glucose is circulating in the blood, but the cells can't absorb it to use it as a fuel. The excess blood sugar molecules also "spill" into the urine, meaning that as the blood filters through the kidneys, some of the sugar comes out of the blood and is not reabsorbed. The extra sugar which is now in the urine causes water molecules to follow (a normal physics principle) and therefore the person with diabetes urinates frequently (the second classic symptom of diabetes). This obviously leads to the third classic symptom, which is frequently being thirsty. The body can sense that excess water is being lost because of the frequent urinating and the normal response is to become thirsty.