What is a blood glucose test?
Glucose is a sugar with many important functions in the body. When you eat, the different sugars in food are converted to glucose and used by the cells for energy. Your glucose must be kept within a certain range, otherwise, it can cause health problems. A blood glucose test measures glucose in the blood at the time of testing.
Elevated blood glucose levels are most likely to be caused by diabetes, but other health conditions can also result in raised blood glucose. Interpretation depends on individual factors such as diabetes/insulin resistance status and medication.
Test results differ if the test is fasting, non-fasting, or taken hours after a meal. Results can indicate whether a person is in the normal range, the prediabetes range, or already suffers from diabetes.
Unless this is ordered as a retest or for a specific reason, we recommend ordering this as part of a health test.
Why test blood glucose?
Blood glucose is an important part of a metabolic panel, as it helps identify conditions like insulin resistance, pre-diabetes, and diabetes, which can often be completely reversed with lifestyle changes. By testing blood glucose levels, you can discover your risk factors for lifestyle diseases in time to take preventive action. Additionally, monitoring changes in your blood values as you make lifestyle changes or undergo treatments is crucial for managing your health. It is important to fast, consuming nothing except water, for at least 10 (preferably 12) hours before taking this test to ensure accurate results.
What causes low blood glucose?
Low glucose levels are most common in diabetics who are taking insulin. This can be avoided by monitoring glucose regularly and through a consistent medical and lifestyle routine. Other causes include vomiting/diarrhea, excess alcohol consumption, excess insulin (hyperinsulinism), low-carbohydrate diet, medicines and diseases of the liver, heart, pancreas, and kidney.
Symptoms of low blood glucose
Low blood glucose, also known as hypoglycemia, can cause a variety of symptoms ranging from mild to severe. Common symptoms include shakiness, excessive sweating, intense hunger, dizziness, and confusion. You might also experience weakness, headaches, irritability, a rapid heartbeat, and blurred vision. If blood glucose levels drop too low, severe symptoms such as seizures, loss of consciousness, and even coma can occur. If you experience these symptoms, it's important to consume a fast-acting carbohydrate like juice or candy and seek medical attention if necessary.
What causes high blood glucose?
Typical causes of high blood glucose include dietary and lifestyle factors. Poor sleep, frequent snacking, overconsumption of processed flour and sugar, some sweeteners, overeating, obesity, and inactivity may all increase blood sugar. High blood glucose can be a sign of insulin resistance or diabetes. Other factors and health conditions that increase blood glucose include menstruation, dehydration, increased need for thiamine (vitamin B1), fatty liver and metabolic syndrome.
Other health conditions that can increase blood glucose include pancreatitis, hyperthyroidism, Cushing syndrome, and acute stress (in response to trauma or illness). Interpretation of this test depends on individual factors such as diabetes/insulin resistance status and medication. Test results differ if the test is fasting, non-fasting or taken hours after a meal. Results can indicate whether a person is in the normal range, the prediabetes range or already suffers from diabetes.
Symptoms of high blood glucose
High blood glucose, also known as hyperglycemia, can cause a range of symptoms that may vary in severity. Common symptoms include frequent urination, increased thirst, and excessive hunger. You might also experience fatigue, blurred vision, and headaches. High blood glucose can lead to unintended weight loss and slow healing of cuts and bruises. In severe cases, it can cause nausea, vomiting, confusion, and even diabetic ketoacidosis, which is a serious condition requiring immediate medical attention. If you notice these symptoms, it's important to consult a doctor for proper evaluation and management.
More information
Insulin, a hormone excreted by the pancreas, helps the body’s cells use or store blood glucose from food. If your body is not able to produce insulin, or insulin is produced but your body’s ability to use it is impaired, as in insulin resistance, glucose remains in your bloodstream. This can result in insulin resistance and type-2 diabetes.
Many different factors, including medication, physical activity, diet, and other biological and environmental factors, affect your blood glucose levels. These are not always easy to control.
Chronic high blood sugar can lead to cardiovascular disease, kidney disease, blindness, neurological damage, and ulcers. Symptoms of poor blood glucose management include fatigue, poor mental capacity, weakness, weight loss, excess thirst, and frequent urination. Some people have no symptoms at all. In the worst case, both high and low blood sugars can lead to unconsciousness.
This test should not be used alone to detect the risk of future diabetes and heart disease. No test should be used alone to determine whether someone has a blood sugar problem. It should ideally be used with HBA1C, triglycerides, C-peptide, and homocysteine.
Preparations for this test
Do not eat or drink anything except water for at least 10 (preferably 12) hours before taking this test.
On the day
Remember to take your ID with you when going to take a test. Arrive early and sit for 15 minutes before the test is taken.