Diagnosing Diabetes with a Blood Test


Diabetes is a common disease that can impact absolutely everyone. When an individual has diabetes, their body is incapable of producing insulin –a hormone responsible for utilizing glucose for energy. This is problematic as this results in the incapability to metabolize carbohydrates leading to elevated levels of glucose in the bloodstream. There are different forms of diabetes, as well as multiple reasons for its onset. For this reason, it is imperative to manage and monitor your health.

Diabetes is a gradually developing disease. Some individuals catch this progression at the prediabetes stage. This stage includes symptoms such as aggravated hunger, weight loss, fatigue, frequent urination, and other symptoms commonly associated with diabetes. Some individuals, however, do not demonstrate any symptoms. For this reason, it is Important to consult your doctor about any concerns and regularly monitor your condition. If you are in the prediabetes stage, it is possible to prevent the condition from progressing through lifestyle changes regarding diet and physical activity.

To diagnose prediabetes or diabetes, most frequently the doctor will rely on blood tests. Due to its efficiency, the Fasting Plasma Glucose Test (FPG) is the most prevalent blood test used. The Fasting Plasma Glucose Test involves overnight fasting where an individual is not to eat or drink for a minimum of eight hours. The fasting is then followed by a blood test. If the fasting blood sugar is over 100 mg/dl and under 125 mg/dl the individual will be diagnosed with prediabetes. If however, the individual’s blood sugar is over 125 mg/dl the individual will be diagnosed with diabetes.


Another test commonly used by physicians is the Oral Glucose Tolerance Test (OGTT). In addition to measuring the fasted blood sugar like the FPG, the OGTT also measures the body’s ability to process glucose over a three-hour period. The OGTT is most prevalently used to diagnose gestational diabetes in pregnant women however, it is also used for diagnosis of traditional forms of diabetes.

For this test to be conducted, the patient will be required to consume a healthy balanced diet of 150 grams of carbohydrates with dietary restrictions for three days. The individual will also be given exercise restrictions to eliminate any interference with the results.

During the OGTT individuals will be asked to drink a glucose solution quickly, and have their blood sugar measured multiple times over the course of up to 3 hours. There are varying thresholds for the OGTT to determine the diagnosis. Prior to drinking the solution, a normal blood sugar is under 100 mg/dl. One hour after the beverage, an individual without diabetes’ blood sugar should be less than 184 mg/dl. Two hours after the beverage, a normal blood sugar is less than 140 mg/dl. If however, an individual exceeds these thresholds they will be diagnosed with pre-diabetes or diabetes.

Blood tests are the most commonly used tool used to diagnose diabetes due to their accuracy. When physicians conduct blood tests to measure blood sugars however, they will often recommend that tests be repeated on a subsequent day to ensure the accuracy of the results. Having your physician regularly monitor your condition can be helpful in terms of preventing cardiovascular disease, nerve damage, kidney damage, foot damage, Alzheimer’s and various other serious health complications associated with diabetes.


*The author of this blog is not a medical professional and this article does not contain professional medical advice. This blog is not intended to substitute for medical advice, treatment, or diagnosis. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of the contents of this article. If you think you may have a medical emergency, call 911 immediately.