As we eat, the body breaks down the carbohydrates into blood glucose (also called blood sugar), which it uses for energy. Insulin is a hormone that the body needs to get glucose from the bloodstream into the cells of the body.
In type 1 diabetes (affecting about 5 percent of people with diabetes), the pancreas does not produce insulin. With the help of insulin therapy and other treatments, even young children can learn to manage their condition and live long, healthy lives. In type 2 diabetes (about 95 percent of people with diabetes), the body does not use insulin properly. This is called insulin resistance. At first, the pancreas makes extra insulin to make up for it. But, over time it isn’t able to keep up and can’t make enough insulin to keep blood glucose at normal levels.
Hypoglycemia is a condition that occurs when one’s blood glucose is lower than normal, usually less than 70 mg/dL. Signs include hunger, nervousness, shakiness, perspiration, dizziness or light-headedness, sleepiness, and confusion. If left untreated, hypoglycemia may lead to unconsciousness. Hypoglycemia (also called an insulin reaction) is treated by consuming a carbohydrate-rich food such as a glucose tablet or juice. It may also be treated with an injection of glucagon if the person is unconscious or unable to swallow.
Hyperglycemia refers to excessive blood glucose. Fasting hyperglycemia is blood glucose above a desirable level after a person has fasted for at least eight hours. Postprandial hyperglycemia is blood glucose above a desirable level one to two hours after a person has eaten. Hyperglycemia can be a serious problem if left untreated, as it can lead to ketoacidosis (diabetic coma). Ketoacidosis develops when the body doesn’t have enough insulin. Without insulin, the body can’t use glucose for fuel, so the body breaks down fats to use for energy. Ketoacidosis is life-threatening and needs immediate treatment. Symptoms include shortness of breath, breath that smells fruity, nausea and vomiting, and very dry mouth.
Source: American Diabetes Association