In a laboratory the blood sugar level is masured from a blood sample, and the result is given as the plasma glucose level (P-gluk, fasting glucose abbreviation fP-gluk). In blood sugar self-monitoring, the samples are normally taken from a fingertip, in which case it is a capillary sample. The blood sugar limit values are slightly different for laboratory tests compared to self-monitoring tests from the fingertip.
Units of blood sugar
In Finland and Europe in general, the unit used for blood sugar is mmol/l. However, in the United States and some other countries, the unit used is mg/dl. The conversion factor between the units is 18. For example, if the blood glucose in the unit used in Finland is 5.6 (mmol/l), it can be converted to mg/dl by multiplying by 18, i.e. 5.6 x 18 = 101 mg/dl. Similarly, if the blood sugar in the US unit of measurement is 180 (mg/dl), it can be converted into mmol/l by dividing it by 18, i.e. 180 / 18 = 10 mmol/l.
This information may be needed, for example, if a person moving to Finland, from for example from the United States, needs to learn to understand blood glucose readings in a new unit of measurement.