Postprandial (PP) Blood Sugar Test

PP blood sugar test, also known as postprandial plasma glucose test is a blood test that measures the levels of glucose in the blood after a meal. The meal needs to contain a set amount of carbohydrate.

In many countries like India, USA, etc. the oral glucose tolerance test is used for diagnosis of glucose intolerance, type 2 diabetes, gestational diabetes, etc.

Like Fasting blood sugar test, HBA1C test, PP blood sugar test is an important test in the treatment of diabetes.

PP Blood Sugar Test Purpose

The purpose of postprandial blood sugar test are the following

  • To screen for diabetes, glucose intolerance, etc.
  • To diagnose gestational diabetes
  • To monitor blood sugar level in blood after a meal
  • To know the appropriate treatment of the patient who is diagnosed with high levels of glucose in the blood
  • To know how the patient is responding to the treatment
  • To determine if there is any need to change the ongoing treatment or medicine
  • To know the overall health status of the patient
  • To know how factors such as stress or illness affect the blood sugar level

PP Blood Sugar Test Importance

The importance of PP blood sugar test are the following 

  • To know the blood sugar level in the blood after a meal. This test gives an idea about how well the pancreas is secreting the insulin hormone and how well the hormone is working in the body
  • To know how much the patient is prone to infection. Usually when there is a high level of glucose (blood sugar) in the blood, it causes infection.

When there is infection already present in the body, high glucose level causes the infection to stay. This is of particular concern because prolonged infection can cause additional health issues.

  • To know how much fit a person is. High level of glucose in the blood leads to diabetes. Diabetes is associated with various health issues such as kidney disease, heart disease, blood vessel diseases, nerve diseases, etc.
  • This test gives an indication that if a person is prone to develop diabetes. This is also known as prediabetes.

A person with prediabetes takes adequate measure (such as avoidance of too much consumption of carbohydrate, adequate physical exercise, avoidance of sedentary lifestyle, etc) to prevent the development of diabetes. 

  • This test helps to know if there is a need to start diabetic medicine. Also, the appropriate timing of the medicine can be determined based on the level of blood glucose in the blood after a meal.

This is of special importance because when the blood sugar rises rapidly in the blood after a meal, insulin should secret from pancreas in adequate amount to make the blood sugar level within normal range in the blood.

When either due to inadequate secretion of insulin or due to inadequate functioning of insulin in the peripheral tissue, the blood sugar level remains high in the blood, then the health hazards due to high blood glucose level starts to develop.

The person may have a fasting blood sugar level within normal range. So as the PP is high, the diabetic medicines should be given after a meal to control the blood sugar level in the blood post meal.

  • The blood sugar level in the blood varies with time. A stable level of blood sugar within normal range is needed to have a healthy life. Based on the diet the sugar level either increases or decreases. So, to choose the proper diet for a person can be determined by PP blood sugar test.
  • PP blood sugar test also helps to detect how much prone a person to develop hypoglycemia, a condition when blood sugar level falls below the normal range. This is a life threatening condition. Immediate intake of glucose is needed if hypoglycemia develops.

PP Blood Sugar Test Procedure

Just like fasting blood sugar test, PP blood sugar test is also a routine blood test. This test needs intake of a set amount of glucose (75 gm). After 2 hour, blood is drawn from vein (preferably vein of the arm). Based on this blood sample, test result is prepared.

PP Blood Sugar Test Target Range

The target range of PP blood sugar test are the following 

2 hour after meal PP blood sugar range

People without diabetes : the blood sugar level should be under 140 mg/dl

People with diabetes: the blood sugar level should be under 180 mg/dl

It is always best to have blood sugar level 2 hour after a meal to be within 140 mg/dl.

PP Blood Sugar Test Range Factors

Target range for PP blood sugar also depends upon the following factors

  1. The duration of diabetes ( that is for how long the diabetes is present)
  2. Pregnancy
  3. Age
  4. Personal medical history
  5. Overall health status
  6. Diabetic complications present or not.

Other factors that can affect PP blood sugar level are

  1. Carbohydrate absorption
  2. Insulin and glucagon secretion
  3. Glucose metabolism in the liver and peripheral tissues
  4. Quantity of the meal containing carbohydrate 
  5. Composition of the meal
  6. Timing of the meal

It is better to take usual regular meals before going for PP blood sugar test to have a better idea about what your PP blood sugar level usually have on other days. If one takes high sugar containing food which one not takes during other days then the PP blood sugar test may show unusual high blood sugar level. So if treatment is provided based on this blood sugar test report, there is a chance of over treatment.

In case one is taking diabetes medicine or medicine for other underlying medical conditions, always consult with the doctor whether you need to discontinue the medicine or not. Usually people who are on diabetes medicine are advised to take the medicine just like other days. Never skip any medicine without consulting with the doctor. Follow the doctor’s instructions. Stay healthy and happy.


  1. Psychiatry, 2 Volume Set Book By Wiley
  2. Year Book of Psychiatry and Applied Mental Health 2012
  3. Textbook of Psychiatry E-Book, Elsevier
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