Glucose, a type of simple sugar, plays a role in providing energy to cells of the body. Blood sugar, a measure of the amount of glucose circulating in the bloodstream, is tightly regulated by a number of hormones to ensure cells have access to the energy they need to support life, and too much or too little blood sugar can cause a number of adverse effects. Hypoglycemia, or low blood sugar, may occur as a result of environmental factors or indicate the presence of an underlying disease.
Exercise
A common cause of temporary hypoglycemia is strenuous exercise, according to the University of Maryland Medical Center. During exercise, cells throughout the body take in sugar from the blood to convert into chemical energy to support sustained cellular functioning. Long periods of exercise or intense exercise decrease blood sugar levels over time. Eating a small snack before working out, and having another small snack after exercising can restore blood sugar levels and prevent the development of symptoms such as lightheadedness or fatigue.
Fasting
Dietary choices and fasting can also cause temporary or chronic low blood sugar, according to the National Diabetes Information Clearinghouse. During digestions, the nutrients from each food consumed get broken down into chemicals the body can use for energy. All carbohydrates and sugars get broken down into glucose, which in turn pays a role in determining blood sugar level. Fasting deprives the body of carbohydrates to metabolize, so the body cannot replace blood sugar, and cells begin to use up blood glucose faster than it can be replenished. Eating small meals throughout the day allows the body to maintain a relatively constant blood sugar level to prevent low blood sugar.
Tumor Growth
Chronic low blood sugar may also indicate the presence of a serious underlying disorder, such as a hormone-secreting tumor. Hormones such as insulin work to lower blood sugar, and tumors resulting in chronically high insulin levels lead to hypoglycemia, as the body is constantly signaled to lower blood sugar. Tumors that release insulin are called insulinomas, and they develop from the insulin-secreting beta cells within the pancreas. Cells within an insulinoma constantly secrete insulin regardless of blood sugar level, and the increase in insulin-secreting activity, along with the overall increase the number of in insulin-secreting cells leads to very high insulin levels. The University of Maryland Medical Center indicates that most insulinomas are treated with surgery, and patients with inoperable tumors receive drug therapy to regulate insulin and blood glucose levels.
