Glucose (blood sugar)
Also written as: Blood sugar, Fasting glucose
The amount of sugar in your blood at the moment of the draw.
What it measures
The concentration of glucose in your blood at the instant the sample was taken. It is a snapshot, not an average.
Why a doctor orders it
Included in routine metabolic panels, used in screening for and monitoring diabetes and prediabetes, and checked when symptoms suggesting high or low blood sugar are described.
What is generally associated with a higher result
Broadly associated with diabetes and prediabetes, with acute illness or stress, with corticosteroids and several other medications, and with having eaten before a draw that was meant to be fasting.
What is generally associated with a lower result
Broadly associated with going a long time without eating, with some diabetes medications, with alcohol, and less commonly with hormonal or liver conditions.
Everyday things that move this number
Not every shift in a value reflects disease. These are ordinary factors known to affect this particular measurement:
- Whether you actually fasted, and for how long
- Illness or physical stress on the day
- Corticosteroids
- A sample that sat too long before processing, which can lower the reading
Questions to take to your appointment
- Was this meant to be a fasting sample, and was I fasting?
- Should an A1C be checked to see the longer-term picture?
Build a printable questionnaire with your own results →
Where to read more
MedlinePlus, from the US National Library of Medicine, publishes patient-facing pages on individual lab tests and is a reliable next stop: medlineplus.gov/lab-tests .
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