Random blood glucose (RBS) measures blood sugar at any time of day, regardless of your last meal.
- Normal range (adults)
- 70–140 mg/dL (3.9–7.8 mmol/L)
- Sample
- Blood
- Fasting
- Not usually needed
- Also called
- RBS, Random Blood Sugar, Random Blood Glucose, Blood Sugar Random, Glucose Random
Random Blood Glucose normal range
| Group | mg/dLConventional units: US, South Asia | mmol/LSI units: UK, Europe, Australia, international |
|---|---|---|
| Adults | 70–140 | 3.9–7.8 |
A random value of 200 mg/dL (11.1 mmol/L) or above with symptoms suggests diabetes.
Your report may use either unit system; labs in the Gulf often print both. Ranges also vary slightly between laboratories, so the range printed on your own report is the one to go by.
Why is the Random Blood Glucose test done?
It is a quick screening test, often used in clinics and emergencies.
What does a high Random Blood Glucose level mean?
A random value of 200 mg/dL (11.1 mmol/L) or above with symptoms such as thirst, frequent urination or weight loss suggests diabetes. Values between 140 and 199 mg/dL need a fasting test or HbA1c.
Common causes
- Diabetes or prediabetes
- A large, carbohydrate-heavy meal shortly before the test
- Stress, illness or steroids
Diet and lifestyle tips
- Reduce sugar and refined carbohydrates
- Eat vegetables and protein first in your meal, carbohydrates last
- Walk after meals
- Confirm with a fasting glucose or HbA1c
What does a low Random Blood Glucose level mean?
A low random glucose can mean hypoglycemia.
Common causes
- Diabetes medicines
- Missed meals
- Alcohol
- Heavy exercise
Diet and lifestyle tips
- Treat symptoms with fast sugar, then a meal
- Regular meals with protein and fibre
When should you see a doctor?
Confirm any high random reading with a fasting glucose or HbA1c.
Last updated
This page is for general education and is not a diagnosis. Normal ranges differ between laboratories, so always compare your result with the reference range printed on your own report, and discuss abnormal results with your doctor.