Blood sugar is a term that most of us have heard before – whether in connection with diabetes, nutrition or a general health check.

What is blood sugar?

Blood sugar refers to the amount of sugar – more precisely glucose – that circulates in our blood. Glucose is the most important source of energy for our body. It comes from food, for example from bread, fruit or sweets, and is absorbed into the blood via the intestines. In order for the cells to be able to use the glucose, the hormone insulin ensures that it enters the cells from the blood. If this mechanism is in balance, blood sugar levels remain stable. If something goes wrong – such as diabetes – it can become too high or too low, which has health consequences.

Why is blood glucose measured?

In medicine, blood sugar is checked to find out whether the metabolism is working properly. Values that are too high can indicate diabetes, while values that are too low can indicate hypoglycemia, which can also be dangerous. However, blood sugar is also an important indicator of general complaints such as tiredness, thirst or weakness. In Germany, the measurement is standard for routine examinations, in emergency medicine or for monitoring known diseases such as diabetes.

How is blood glucose determined in laboratory medicine?

In Germany, there are various methods for measuring blood sugar. In most cases, blood is taken – either from the fingertip (capillary blood) or from a vein (venous blood). Here are the most common approaches:

1. Fasting blood glucose: This measurement is taken in the morning before you eat or drink anything (except water). It shows how the body regulates sugar at rest. Typical values are between 70 and 100 milligrams per deciliter (mg/dl). If the value is higher, this could be an indication of diabetes.
   
2. Stress test (oGTT): In the oral glucose tolerance test, you drink a sugar solution and your blood sugar is then measured several times – usually after two hours. This shows how well the body can cope with a sugar intake. Values above 200 mg/dl after two hours are considered abnormal.
   
3. Long-term value (HbA1c): This value does not measure the current blood sugar, but shows how high it has been on average over the last two to three months. The HbA1c is given as a percentage or millimoles per mole and is particularly important for monitoring diabetes. A value below 5.7% is considered normal.
   
4. Rapid test: A small device called a blood glucose meter is often used in doctors’ surgeries or at home. With a prick of the finger and a test strip, you have a result in seconds. This is practical, but less accurate than laboratory measurements.

In laboratories in Germany, blood is analyzed with precise devices that use chemical reactions to determine the amount of glucose. The results are then compared with reference intervals – a range that shows what is normal in healthy people.

Special features in Germany

Laboratory medicine in Germany is highly regulated in order to guarantee reliable results. Laboratories must adhere to high quality standards and the measurement methods are standardized. There are also clear guidelines as to when which tests should be carried out – for example, if diabetes is suspected or during pregnancy, when blood sugar levels are regularly tested to rule out gestational diabetes. The costs of such tests are usually covered by health insurance if they are medically necessary.

What do the results mean?

A normal blood glucose value depends on when and how it was measured. If it is outside the reference range, the doctor will take a closer look: a high fasting value (e.g. over 126 mg/dl) could mean type 2 diabetes, a low value (under 50 mg/dl) could mean hypoglycaemia, for example due to too much insulin. It is important to note that a single value is not sufficient for a diagnosis. Symptoms, further tests and lifestyle are always taken into account.

Conclusion

The determination of blood sugar in laboratory medicine is a window into our metabolism. In Germany, doctors use modern technology and clear standards to find out whether everything is in balance. Whether for routine checks or to monitor diseases – the measurement helps to identify and treat problems at an early stage. For us, this means that by taking a look at our blood sugar, we can better understand how our body is doing – and act in good time if in doubt.

Matching:

Blood glucose monitoring for diabetes: patches instead of pricks – MedLabPortal

World first: Dexcom G7 transmits blood glucose values to Apple Watch – MedLabPortal

Editorial office: X-Press Journalistenbüro GbR

Gender note. The personal designations used in this text always refer equally to female, male and diverse persons. Double/triple references and gendered designations are avoided for the sake of better readability ected.