Fasting Blood Glucose
Glucose is the body's main source of energy. The hormone insulin helps cells take glucose out of the blood. When insulin stops working as it should, more sugar stays in the blood and the value rises. A fasting test measures your blood glucose at a single point in time. Your sample is analysed at an accredited Swedish laboratory and reported with the laboratory's reference interval.
Why Test Blood Glucose?
Rising blood glucose rarely causes symptoms at first, so a test can show a change before you notice anything yourself. It is particularly relevant if diabetes runs in your family, if you carry weight around your waist, or if you have high blood pressure or raised blood lipids. It is also used to follow the effect of changes to diet and exercise. Fasting glucose is often combined with HbA1c, which reflects average blood glucose over a longer period.
What Do High Blood Glucose Levels Mean?
A raised fasting glucose can indicate insulin resistance, pre-diabetes or type 2 diabetes. It can also be temporarily raised during acute illness, severe stress, corticosteroid treatment and with certain other medicines. A diagnosis is never made from a single test: the value needs to be confirmed on a separate occasion and assessed alongside HbA1c and your wider health.
What Do Low Blood Glucose Levels Mean?
Low blood glucose (hypoglycaemia) is uncommon in people who do not have diabetes. It is seen mainly with insulin treatment or certain diabetes tablets. Other causes include prolonged fasting, alcohol, and liver or kidney disease. Recurrent shaking, sweating and dizziness should be assessed by a doctor.
Symptoms to Watch For
- Increased thirst and passing large amounts of urine (high value)
- Fatigue and lack of energy
- Blurred vision
- Wounds that heal slowly
- Unintended weight loss (high value)
- Shaking and trembling (low value)
- Sweating and dizziness (low value)
- Difficulty concentrating or confusion
- Strong hunger
- Palpitations (low value)
Who Should Get Tested?
- People with diabetes or metabolic syndrome in the family
- People carrying extra weight, particularly around the waist, or who move little
- People who are often thirsty, pass urine frequently, or are tired without explanation
- People following how diet and exercise affect their blood glucose
- People who have had gestational diabetes
- People with high blood pressure or raised blood lipids
How to Prepare for Your Test
Fast for at least ten hours before the test. You may drink water. Bring valid ID to your appointment. If you take medicines for diabetes, ask your doctor whether to take them as usual before the test.
Order Your Blood Test
Test your Blood Glucose levels with an accredited Swedish laboratory. Results within days, reviewed by Wellth.
Frequently Asked Questions
What is a normal fasting blood glucose?
What is the difference between blood glucose and HbA1c?
Can I lower my blood glucose without medication?
How often should I test?
Reviewed by
Wellth Team
Wellth
Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.
Learn more about our team →Medical Disclaimer
The information on this page is provided for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Wellth provides health information and testing services but is not a substitute for clinical care. Always consult a qualified healthcare provider if you have questions about a medical condition. If you are experiencing severe or urgent symptoms, contact your doctor or call 1177 Vårdguiden. Blood test results should be interpreted by a qualified healthcare professional in the context of your complete medical history.