Blood Glucose
Glucose is the primary energy source for the body's cells. Blood glucose level (glycemia) is a key marker of carbohydrate metabolism and a fundamental test for diagnosing diabetes mellitus.
Disclaimer. This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider for interpretation of test results.
What the Test Shows
A blood glucose test measures sugar concentration in blood plasma. It is used for:
- Diabetes screening
- Monitoring treatment effectiveness
- Evaluating symptoms of hypo- or hyperglycemia
- Routine health checkups
Normal Ranges
| Group | Fasting (mmol/L) | Fasting (mg/dL) | 2h Postprandial |
|---|---|---|---|
| Adults | 3.9–5.5 | 70–99 | < 7.8 mmol/L (140 mg/dL) |
| Children (< 14 y) | 3.3–5.5 | 60–99 | < 7.8 mmol/L |
| Pregnant | 4.0–5.1 | 72–92 | < 8.5 mmol/L |
Causes of Elevated Glucose (Hyperglycemia)
- Type 1 and Type 2 diabetes mellitus
- Pancreatitis, pancreatic tumors
- Hyperthyroidism, Cushing's syndrome
- Stress, infections, trauma
- Medications (corticosteroids, thiazide diuretics)
Causes of Low Glucose (Hypoglycemia)
- Insulin or oral hypoglycemic overdose
- Prolonged fasting
- Insulinoma
- Severe liver disease
- Adrenal insufficiency
Related Biomarkers
- HbA1c (Glycated Hemoglobin) — reflects average glucose over 2–3 months
- Ferritin — iron deficiency can affect HbA1c results
- CRP (C-Reactive Protein) — inflammation marker, often elevated in uncontrolled diabetes
How to Prepare
- Blood should be drawn fasting (8–12 hours without food).
- Avoid strenuous exercise the day before.
- Do not smoke for 30 minutes before the test.
- Inform your doctor about any medications you are taking.
Tracking and Monitoring
Monitoring glucose trends over time helps identify patterns and adjust therapy promptly. Lissa Health automatically visualizes your test history and highlights deviations from normal ranges.
FAQ
Can I drink water before the test? Yes, plain still water is allowed.
How often should I check my glucose? Healthy adults — every 1–3 years. With risk factors (obesity, family history) — annually. Diabetic patients — as directed by their physician.
What should I do if glucose is elevated? Consult an endocrinologist for further evaluation: oral glucose tolerance test, HbA1c, insulin levels.
Last updated: June 2026