Human body cells need glucose to produce energy, and brain cells require it to function properly. Our body uses glucose with the help of insulin, a hormone secreted by pancreas. Insulin regulates the transport of glucose to needy cells and guides the body to store unused glucose as glycogen or as triglycerides in adipose cells.

Glucose test is necessary to determine the amount of glucose in blood. It helps diagnose and monitor patients suffering from hyperglycemia or hypoglycemia. Severe hyperglycemia or hypoglycemia can be fatal, as it causes organ failure, brain damage, coma, and may be death of the patient.

The glucose level rises in body slightly after meals. The pancreas secretes insulin to lower the glucose level accordig to the type of meal taken. If the level of blood glucose falls to low, then pancreas secretes another hormone called glucagon, which converts some glycogen into glucose, and thus elevating the glucose level in the body.

Chronic level oh high blood glucose slowly damages all vital body organs, such as kidneys, eyes, heart and blood vessels, and nervous system. Some pregnant women develop hyperglycemia during pregnancy, which causes gestational diabetes. If not treated properly, the newborn babies can be of large size and may have low level of blood glucose.

Glucose test should be done on fasting. There are various categories of glucose test, which include fasting blood sugar (12 hours after meal), postprandial (2 hours after meal), and glucose tolerance test (continuous testing).