Random Blood Sugar
A blood sugar test taken at any time, regardless of meals.
Quick Summary
For quick checks of blood sugar, for example in someone unwell or with symptoms of diabetes.
Blood glucose.
No preparation.
Overview
A random sugar of 200 mg/dL or more with symptoms suggests diabetes.
Fasting sugar or HbA1c confirms the diagnosis.
What It Measures
Glucose
At the time of testing.
How It's Performed
- 01
Preparation
Usually no special preparation unless your doctor advises.
- 02
Blood sample
A small amount of blood is taken from a vein in your arm.
- 03
Afterwards
Press on the spot; a small bruise is common.
Interpreting Results & Next Steps
Discuss with Doctor
Normal ranges differ between laboratories; use the range on your report. Your doctor will explain what your result means and what happens next.
If values are Low:
Low sugar can cause confusion and needs treatment.
If values are High:
200 or above with symptoms suggests diabetes.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Blood Glucose Test(opens in a new tab) · MedlinePlus, US National Library of Medicine