A fasting blood glucose test measures the amount of glucose -- or sugar -- in the blood at the exact time the sample is taken, without the interference of outside factors such as food or beverages that may affect the results. Your doctor may order this test to diagnose pre-diabetes, low blood sugar and high blood sugar, according to Lab Tests Online. If you are pregnant, your doctor typically orders this test to rule out gestational diabetes, which is a temporary form of high blood sugar. Some preparation is necessary prior to testing.
Step 1
Make more time for your questions. This can be done by preparing yourself for any questions the doctor might ask you before scheduling your glucose blood test. He might ask if you have experienced any change in your weight, have a family history if diabetes and if you exercise regularly, according to MayoClinic.com.
Step 2
Write down any symptoms you have. Aside from normal symptoms of diabetes such as excess thirst, an increase in urination, confusion and blurred vision, you need to write down any symptoms that do not relate to diabetes. Other medical conditions such as Cushing Syndrome, pancreatitis and hyperthyroidism can also cause high glucose levels. Knowing this ahead of time allows your doctor to rule these conditions out when diagnosing diabetes.
Step 3
Write down all medications you take. Just as medical conditions can result in high blood sugar, certain medications can as well. These include tricyclic antidepressants, diuretics, lithium and birth control pills containing estrogen, according to Lab Tests Online.
Step 4
Ask what your specific instructions are. Most fasting glucose tests do not allow you any food or beverages eight hours before the test. In some cases, it is a 10-hour fast, according to Lab Tests Online.
Step 5
Make your appointment for the morning. Because you have to fast, be sure to make your appointment for the morning. This means less time going without food and drink throughout the day.
Step 6
Eat later the night before. Plan your dinner a bit later the night before your test. This might ease the hunger pains you might feel while waiting for your appointment the next day. In addition, if you can drink until midnight the night before the test, you may want to sip water or some type of beverage as close to bedtime as you can to avoid thirst as well.
