Random Blood Glucose Test

A random blood glucose test measures how much sugar (glucose) you have in your blood at the time you are tested. This test is sometimes called the casual glucose test.1

If your blood glucose level is 200 mg/dL or higher, you likely have diabetes.1,2

Why is a random blood glucose test important?

Tests like the blood glucose test give you and your doctor important information about your health. Your doctor might have you take a random blood glucose test if you have any of the common signs of high blood glucose, like:3

  • Blurred vision
  • Frequent infections
  • Numbness or tingling, especially in the legs, feet, arms, and hands
  • Sores or cuts that heal slowly or do not heal
  • Excessive thirst and increased urination
  • Sudden, unexplained weight loss
  • Fatigue
  • Constant hunger
  • Fatigue

You might also be asked to take a random blood sugar test if you have any of the risk factors for type 2 diabetes, including high blood pressure and being overweight.3

In type 2 diabetes, the body works hard to release enough insulin to keep blood glucose levels down. Eventually, the body cannot make enough insulin to keep up. Since there is not enough insulin to move glucose into the cells and the cells are unable to respond to insulin, it stays in the blood instead.3

Type 2 diabetes increases your risk for many serious health problems, especially if it is left untreated. Over time, high blood sugar causes damage to the body’s organs and systems. If you have symptoms of diabetes or have risk factors for type 2 diabetes, the random blood glucose test can help you get diagnosed and the right treatment sooner.

How is a random blood glucose test done?

A random glucose test is a quick test that can be done in your doctor’s office or a lab at any time. Unlike with a fasting blood glucose test, you do not need to fast (not eat or drink anything but water) before your random blood sugar test.1

Before your test tell your doctor about any medicines you are taking or if you are sick since these can affect the results.1

Your doctor or a member of your healthcare team will take a small sample of your blood, usually from your finger. They will then measure the amount of glucose that is in your blood. Results are usually available quickly.1

What do the results mean?

Blood sugar levels slightly change throughout the day depending on when and what you eat. However, people who do not have diabetes usually have a blood glucose level around 125 mg/dL or lower. A blood glucose level of 200 of mg/dL or higher typically means you have diabetes.1

If your blood glucose level was above 200 mg/dL, your doctor will probably have you take another random blood sugar test on another day to recheck your glucose levels. You might also have to take a different type of test to confirm your diagnosis. Other tests that are commonly used to diagnose diabetes include:2

If your tests show that you have type 2 diabetes, talk to your doctor about ways to manage your blood sugar and live a healthy life.

How was your type 2 diabetes diagnosed?

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Written by: Heather Morse | Last reviewed: October 2020.