random glucose testing
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What is Random Glucose Testing?

For people suffering from diabetes, it is imperative to keep a check on their glucose levels at random intervals of time. Random Glucose Test (RBS) is a test that evaluates the glucose level or amount of sugar flowing through the body at any given moment. Random Glucose Testing is extremely useful for patients with severe and prolonged diabetic issues.  Also know how to get freedom from diabetes?

Random Glucose Testing is said as “Random” because the test is performed outside any scheduled timeframe, and the observed results are instantaneous. It is of the utmost importance to keep checking the glucose levels at random intervals. This helps the person suffering from diabetes to control the blood glucose levels. Also know about pp sugar range

  Result*      A1C test   Fasting Blood Sugar test Glucose Tolerance test Random Blood Sugar test
  Diabetes   6.5% or above    126 mg/dL or above       200 mg/dL or above      200 mg/dL or above  
Prediabetes    5.7-6.4%        100 - 125 mg/dL         140 - 199 mg/dL               N/A          
   Normal     Below 5.7%       99 mg/dL or below       140 mg/dL or below             N/A          

      Table 1: Various tests indicating the blood glucose level for Diabetic, Prediabetic, and Normal.

What is diabetes?

Diabetes is a disease that affects the ability of the body to secrete insulin from the pancreas. Insulin hormone is vital as it regulates glucose uptake in the cells. Irregular insulin secretion causes a greater concentration of glucose and thus the high blood glucose levels in diabetic patients. The diagnosis is usually made by testing the glucose levels at random intervals of time. This form of diabetes is called Diabetes Mellitus. Diabetes mellitus is a chronic disease affecting more than half of the human population. Primary organs like the heart, kidney, eyes, and nerves are affected by this disease.

  • The normal concentration of blood glucose level is considered as 100 mg/dL.
  • Any blood glucose level more than 200 mg/dL is considered diabetic.
  • Blood glucose level from 140 mg/dL to 200mg/dL is considered prediabetic, meaning that the patient is prone to develop diabetes.

Another form of diabetes, like the diabetes insipidus, results in an imbalance of fluids in the body due to hyposecretion of antidiuretic hormone (ADH). However, Diabetes Insipidus is less prevalent than Diabetes Mellitus. Also know about pp blood sugar

When to go for Random Glucose Testing?

Random glucose testing can be done at any time. Patients who are diabetic need to monitor their blood glucose levels from time to time to keep themselves healthy. glucose random test should be done if you feel these symptoms.

  • Blurred vision
  • Sudden palpitation
  • Feeling extremely tired suddenly
  • Feeling nauseous

Other symptoms of diabetes also include

  • Weight Loss
  • Feeling of thirst and frequent urination
  • Fatigue
  • Slow healing of wounds and difficulty in blood clotting .Also know about blood sugar post prandial

What are the other types of Glucose Testing?

Diabetes is an extremely complex disease that affects various vital organs, and treating it is not easy, considering if the patient has other complications and diseases. Moreover, many medicines also have side effects which contribute to the overall disease. Comorbidity is a real issue when it comes to the treatment of diabetes. As a result, only random glucose testing is not enough to understand and treat the disease. Know about gestational diabetes treatment.

Other tests include A1C Test, Fasting Blood Sugar Test, Oral Glucose Tolerance Test, Glucose Screening Test.

Fasting Glucose Test

A fasting glucose test is a form of testing random glucose levels in the body. It is tested early in the morning, right after waking up and before having any food or drinks. The idea of this test is to check the blood glucose level before any intake of food.

Fasting Glucose Test

For the preparation of the test, it is mandatory not to have any food or drink except for water for 8 to 12 hours.


  • Fasting for 8 to 12 hours is mandatory
  • The test is usually performed early in the morning.
  • The doctor will clean the elbow and the arm region, with 70% alcohol for sterilisation purposes, from where the blood will be drawn.
  • An elastic band will be fastened above the arm to initiate swelling of the vessels.
  • Blood is drawn into a vial or syringe depending on the required blood volume for the tests.
  • Then the needle is then removed, and a band-aid is placed on the puncture site.
  • Then the needle is removed and a band-aid is placed on the puncture site.
  • The blood is sent to pathology labs for testing.

                        Type of Test                         Normal blood glucose range for people without diabetes Normal blood glucose range for people with diabetes
                        Fasting test                              less than 99 milligrams per deciliter (mg/dL)                   between 80 and 130 mg/dL              
2 hours after beginning a meal (postprandial plasma glucose)                   less than 140 mg/dL                                   less than 180 mg/dL                

Read more about  fasting blood sugar levels.

Oral Glucose Tolerance Test

Oral Glucose Test is done to test the different types of diabetes in a patient. The test is done to monitor the acceptance of glucose by the body. OGTT is done to find if the patient has


  • The patient needs to fast for at least 8 hours before the conduction of the test.
  • The patient then is asked to drink 8 ounces (237 millilitres) of a glucose solution containing 3.5 ounces (100 grams) of sugar.
  • Then after 2 hours, a blood glucose test is done to check the sugar uptake capability of the body.
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How does the test work?

A glucose test is a random blood sugar level test that checks the levels of glucose in one’s body. The procedure of a random blood sugar test usually involves making a tiny cut on the finger in order to collect a few drops of blood or pricking the finger. After that, a drop of this blood is wiped onto a test strip, which subsequently provides a reading for the amount of glucose in the blood to determine random blood sugar range. This test greatly benefits people with diabetes as conducting these random blood sugar tests gives a much needed insight into the severity of a person’s diabetic condition. The information that this test provides can be used to treat a person effectively. 

This is a simple test that can be conducted by a physician or nurse in a clinic. For this test, it is not required to fast beforehand as it can be conducted throughout the day. If a person takes a glucose test and the random blood sugar level is 180 mg/dl or above, this suggests that they may have pre-diabetes/diabetes. However, in order to get a more accurate diagnosis, most doctors conduct this test twice and also prescribe other tests that have a higher accuracy level. Also read about glucose in urine

What are the reasons that can affect the results?

While most tests for diabetes require fasting before giving the blood sample, the random plasma glucose test isn’t one of them and can be conducted anytime during the day. However, the level of glucose in the blood tends to fluctuate throughout the day due to a number of different reasons. These may include the amount of food that a person consumes as well as the intensity and amount of time spent exercising or engaging in other forms of physical activity on that particular day. Blood glucose levels in those who do not have diabetes, on the other hand, are more likely to remain within the normal range. The random blood sugar normal range falls below 200 mg/dl. The levels of glucose in a person's blood might be raised as a result of the following factors:

  • eating an excessive amount of food or eating more than usual
  • reduced levels of physical activity 
  • Side effects of certain medication 
  • sickness, stress and discomfort 
  • Menstruation
  • dehydration

A person’s glucose levels can fall just as easily as they rise and here are a few factors that contribute to decreased levels of glucose in a person's blood:

  • eating very little or skipping a meal altogether
  • drinking alcohol 
  • experiencing negative effects from medicines
  • arduous or extensive physical exertion
  • Intensive workout

These are the commonly occurring instances where random glucose levels can be affected so in order to get an absolute diagnosis, most doctors advise conducting additional tests like fasting glucose test or oral glucose tests.

Also read about sugar free sweeteners

What is Random or casual plasma glucose test?

Random Plasma Glucose Test

A test called a plasma glucose test may determine how much sugar or glucose is circulating in your blood at any one time. The concept of having your blood collected at an unscheduled moment in a laboratory is what is meant by "random" or "casual." It makes no difference for the test whether you have been fasting or have eaten within the last several hours. If you do a test for plasma glucose and get a reading that is equal to or higher than 200 milligrams per deciliter (mg/dl), this suggests that you could have diabetes. To be absolutely certain, you will need to conduct additional tests. Alternatively, you may take a test to determine your fasting plasma glucose level or your oral glucose tolerance.

What does a random plasma glucose test involve?

A random plasma glucose test involves collecting a few drops of blood at any given point of the day and depositing the blood on a test strip. This test strip will then show a reading which will determine whether or not a person has diabetes. The random sugar range below 200 mg/dl is considered safe and non problematic and anything higher than that suggests the development of diabetes.


For Type 2 diabetes

  • A normal blood glucose level is lower than 140 mg/dL (7.8 mmol/L).
  •  A blood glucose level between 140 and 199 mg/dL (7.8 and 11 mmol/L) is considered prediabetes. The patient has a risk of developing diabetes.
  • A blood glucose level of 200 mg/dL (11.1 mmol/L) or higher may indicate diabetes.

For Gestational Diabetes

  • A normal fasting blood glucose level is lower than 95 mg/dL (5.3 mmol/L).
  • One hour after drinking the glucose solution, blood glucose level is greater than 180 mg/dL (10 mmol/L).
  • Two hours after drinking the glucose solution, the blood glucose level is greater than 155 mg/dL (8.6 mmol/L).
  • Three hours after drinking the glucose solution, the blood glucose level is greater than 140 mg/dL (7.8 mmol/L).


Diabetes is a very common yet serious disease, though with the right medications and monitoring it can be kept under control. Thus, it is always best to remain diabetes free and ensure a proper lifestyle, healthy food and exercise to stay away from diabetes. Also read how diabetes home test works and it's accuracy.


Why is my blood sugar high in the morning but normal all day?

Our body goes through hormonal changes while asleep, especially at night. This incident happens because the body increases the body glucose level while we are sleeping. It is easier for the body to wake up and start functioning as glucose is a polysaccharide that provides energy to the body to sustain vital functions. This is why blood sugar levels are higher in the morning than all day, irrespective of whether anyone has diabetes.

Is a random glucose test accurate?

Conducting a glucose random test is necessary. It will give you an idea of how your blood sugar levels are acting beyond the set definitions of sugar testing. This will also help you understand your patterns during different times of the day. You can use your glucometer to conduct these random tests at random times of the day. As long as your glucometer is properly calibrated and accurate, the results that you obtain would also be accurate. To ensure this, you can keep testing the numbers of the glucometer against the lab numbers. You can also test your sugars with the same prick and squeeze on different sugar test machines.

Does a random glucose test require fasting?

A blood glucose random test would not require fasting. Since this test is meant to be conducted at any time of the day, it would not be necessary to give it a gap of 8 to 10 hours after a meal. These tests are not supposed to be a measure of the fasting level of sugars. These are conducted to gain a better understanding of how your levels remain throughout the day and the regulation of insulin in the body – with or without injections- depending on your condition.

Can a random glucose test diagnose diabetes?

No, a random glucose test cannot be a diagnostic test in itself. Random glucose levels, however, can give you an understanding of whether or not your sugars are primarily in the normal range. If you notice that your sugars are higher or lower, that can be a criterion for you to go get your HbA1c and other diabetes tests done for a proper diagnosis. This test, stand-alone, cannot provide a conclusive diagnosis of diabetes. It can be a good starting point and measure.

What should be the random blood sugar level?

A random blood sugar level is when a person is tested for diabetes randomly throughout the day. During this, a few drops of a person’s blood is deposited on a diabetes test strip in order to determine their blood glucose levels. Once the test strip shows the results it can be determined if a person has diabetes or not. The normal random blood sugar level should be below 200 mg/dl and a reading higher than that suggests that the person has diabetes.


  • https://www.medicalnewstoday.com/articles/323022


This website's content is provided only for educational reasons and is not meant to be a replacement for professional medical advice. Due to individual differences, the reader should contact their physician to decide whether the material is applicable to their case.