Understanding Normal Blood Sugar Levels in Adults

Knowing your blood sugar levels is important for overall health and well-being. It is especially important for those who have diabetes, a condition that affects the way your body processes sugar. 

But what are normal blood sugar levels for adults, children, and pregnant women? And what are the signs of abnormal blood sugar levels? 

In this article, we will explore the answers to these questions and more. We will discuss what normal blood sugar levels are and why they are important, as well as provide information on what to look out for if your blood sugar levels are outside of the normal range.


  • What is Diabetes?
  • Diabetes and Your Blood Sugar Levels
  • Measuring Your Blood Sugar Levels
  • Normal Blood Sugar Levels in Adults 
  • Normal Blood Sugar Levels in Pregnancy
  • Normal Blood Sugar Levels in Children
  • Abnormal Blood Sugar Levels
  • How Can You Maintain Normal Blood Sugar Levels?
  • When to See a Doctor?
  • Don’t Have Time To Read? 
  • FAQs

What is Diabetes Mellitus?

Diabetes mellitus, commonly known as diabetes, is a condition that affects your body’s ability to produce or use a hormone called insulin, which causes high blood glucose (sugar) levels. 

Your body digests the food you eat and turns it into glucose or sugar, which gets absorbed into your blood and transported to all the cells in your body. Insulin, a hormone produced by the beta cells in the pancreas, helps the glucose in your blood to enter your cells, where glucose becomes your body’s primary source of energy. 


When your pancreas cannot produce enough insulin, or when your body is unable to use the insulin properly, glucose cannot enter your cells and remains in your bloodstream. Persistently high blood glucose levels can lead to several serious and life-altering health complications caused by damage to important organs like your heart, eyes, kidneys, etc.

Types of Diabetes

There are many different types of diabetes, but the most common forms are:

A. Type 1 Diabetes

If you have Type 1 Diabetes, your body produces little or no insulin. It is an autoimmune disorder where most of the insulin-producing beta cells in your pancreas are destroyed. 

Type 1 Diabetes most commonly occurs in children. It cannot be cured or prevented. About 5 to 10% of all the diagnosed cases of diabetes around the world are Type 1.

B. Type 2 Diabetes

If you have Type 2 Diabetes, your body is unable to use insulin efficiently, which causes high blood glucose levels. It is a lifestyle disorder that can be prevented. 

Type 2 Diabetes most commonly occurs in adults over the age of 40 years. However, recently more and more Type 2 cases are being diagnosed in young adults and even children, owing to factors like a sedentary lifestyle and unhealthy diets. 

It is the most common type of diabetes, amounting to about 90 to 95% of the diagnosed cases around the world.

C. Gestational Diabetes

It is a form of diabetes that occurs during pregnancy, usually between the 24th and 28th week. Gestational diabetes causes high blood glucose levels that can affect the health of both the mother and the child. 


In most women with gestational diabetes, the blood glucose levels return to normal after they give birth.


Though technically not a form of diabetes, prediabetes is a precursor to the condition. Here’s more about it:


D. Prediabetes

If you have prediabetes, your blood sugar levels are high, but not high enough to be diagnosed as diabetes. It occurs when your cells develop some insulin resistance or when the beta cells in your pancreas are not making enough insulin to keep your blood sugar levels in the normal range.


Diabetes and Your Blood Sugar Levels

In Type 1 Diabetes, the lack of insulin production means that the glucose in your blood is unable to enter your cells. This leads to your cells being unable to use glucose for energy, and your blood glucose levels rising.  


In Type 2 Diabetes, your body becomes resistant to the effects of insulin. Insulin resistance is a phenomenon where your body produces sufficient insulin, but your cells are unable to respond to and utilize it. This results in sugar remaining in your blood instead of entering your cells.


In gestational diabetes, the hormones produced during pregnancy can interfere with the function of insulin. As the amount of these hormones increases with the progression of your pregnancy, your cells become more and more insulin resistant, leading to high blood sugar levels. 


Diabetes and blood sugar levels in adults


When insulin resistance occurs, the pancreas tries to compensate by producing more insulin. However, over time, the pancreas may not be able to keep up with the body’s demands for insulin, leading to an increase in blood sugar levels. This can result in symptoms such as increased thirst and urination, weight loss, and fatigue. 

Diabetes is diagnosed by measuring your blood glucose levels several times during the day (before and after meals, at random points during the day, etc.) in order to detect impaired glucose metabolism and insulin functioning. In the upcoming sections, we discuss how blood glucose (sugar) levels are measured.

Measuring Your Blood Sugar Levels

First, let’s understand the terms used when measuring and recording blood sugar levels. These parameters are used to diagnose diabetes as well as monitor the effectiveness of diabetes treatment.


Before making a diabetes diagnosis, your doctor will prescribe blood sugar testing, which is generally performed in a diagnostic lab. During treatment, results from both at-home testing and lab tests can be used to monitor the effectiveness of treatment.


1. Lab Testing 

The following are the commonly prescribed lab tests for the diagnosis of diabetes and frequent monitoring of blood sugar levels.


A. Fasting Sugar Levels (Before Meals) Test

The fasting blood sugar test, also known as the FBS test or fasting glucose test, measures the amount of glucose present in your blood after fasting for 8 to 12 hours or overnight. 


The following fasting blood sugar levels chart shows the values that are used as the diagnostic criteria for pre-diabetes and diabetes, as suggested by the American Diabetes Association (ADA).

Inference Normal Pre-diabetic Diabetic
Fasting Blood Sugar Level < 100 mg/dL 100 to 125 mg/dL > 125 mg/dL


B. Post-prandial Sugar Levels (After Meals) Test

The postprandial blood sugar test or the PPBS test measures the level of glucose (sugar) in your blood, one to two hours after eating a meal.


The following postprandial blood sugar levels chart shows the values that are used as the diagnostic criteria for pre-diabetes and diabetes, as suggested by the American Diabetes Association.

Inference Normal Pre-diabetic Diabetic
Postprandial Blood Sugar Level (2 hrs after a meal) < 140 mg/dL 140 to 200 mg/dL > 200 mg/dL


C. Random Blood Sugar Levels Test

The random blood glucose test, also called the random plasma glucose test or RBS test, measures the amount of glucose present in your blood at the time your blood is drawn. This test does not require fasting or eating a meal.


The following random blood sugar level chart shows the values that are used as the suggested diagnostic criteria to detect prediabetes and diabetes by the National Institute for Clinical Excellence (NICE).

Inference Normal Diabetic
Random Blood Sugar Level < 200 mg/dL > 200 mg/dL


D. HbA1c Test

The HbA1c test, also called the A1c test or glycated hemoglobin test, measures the average level of blood sugar (glucose) over the past 2 to 3 months. It does this by measuring the percentage of hemoglobin (a protein in red blood cells) that is coated with sugar.


Hemoglobin helps carry oxygen to different organs. Glycosylated or glycated hemoglobin is formed when the glucose present in your blood attaches itself to hemoglobin. The A1C test measures the average blood glucose levels in the body over 2 to 3 months, as that is the average lifespan of red blood cells.

The following HbA1c levels chart shows the values that are used as the suggested diagnostic criteria to detect prediabetes and diabetes by the American Diabetes Association to detect prediabetes and diabetes.

Inference Normal Pre-diabetic Diabetic
HbA1c Levels < 5.7% 5.7 to 6.4% ≥ 6.5%


To know more about the HbA1c test, check out this video where Dr. Chinmay Patkar explains its importance and how it is done.

Is your blood sugar under control? Book a lab test to check now.


2. At-Home Diabetes Testing

Monitoring your blood glucose levels is easy and can be done from the comfort of your home using the following devices:

A. Glucometer:

A glucometer is a small, hand-held device that helps you record your blood glucose levels. You can check your blood glucose levels by pricking your finger with a sterile lancet and placing a drop of blood on the test strip that is attached to the device. The digital screen displays the amount of glucose present in your bloodstream at that moment.


You can use a glucometer to measure fasting sugar levels, postprandial sugar levels and random sugar levels.


B. Flash Glucose Monitoring (FGM) System:

This glucose monitoring system comes with a reader and a sensor patch that can automatically track your blood glucose levels 24/7. The sensor is a coin-sized patch that is attached to your upper arm and has a very fine needle that is inserted into your skin. The device can capture the readings of your glucose levels when held over the sensor patch. 

The flash glucose monitoring system provides a more comprehensive look into how your blood glucose levels are affected by your meals, physical activity, sleep, etc., and can help you have better control of your blood glucose levels.

Flash glucose monitoring (FGM) device used for measuring normal blood sugar levels in adults

C. Continuous Glucose Monitoring (CGM) System:

Similar to the FGM system, the continuous glucose monitoring system also comes with a sensor patch that sits under your skin and records your blood glucose readings throughout the day. These readings are wirelessly sent to your device or phone, without the need for scanning the sensor with a reader. 


The continuous glucose monitoring system provides all the same benefits as a flash glucose monitoring system, with the added convenience of having the blood glucose readings ready without having to scan the sensor.

Now check your blood sugar levels from the comfort of your home! Shop from our wide range of glucometers and CGM devices and get great discounts.


Normal Blood Sugar Levels in Adults 

In this section, we discuss the normal blood sugar level ranges in healthy adults (20 years or older) and the target blood sugar ranges set for diabetic adults by health agencies like American Diabetes Association (ADA) and the Centers for Disease Control and Prevention (CDC).


It is to be noted that the normal blood sugar levels in adult males and females are similar, and that the blood sugar levels do not differ much with age. 

1. Normal Blood Sugar Levels in Healthy Adults 

The following are the parameters set by the American Diabetes Association (ADA):

Inference HbA1c Levels Fasting Blood Sugar Levels 2 hours After a Meal
Normal Lower than 5.7% Under 100 mg/dL Under 140 mg/dL
Prediabetes 5.7 to 6.4% 100 to 125 mg/dL 140 to 200 mg/dL
Diabetes 6.5% or higher Over 125 mg/dL Over 200 mg/dL


2. Target Blood Sugar Levels for Diabetic Adults

Normal blood sugar levels in diabetic adults or target blood sugar levels are the specific range of blood sugar levels that a person with diabetes should aim to maintain in order to avoid long-term complications.

The American Diabetes Association recommends the following blood sugar level targets for most adults with diabetes.



Target Levels for Diabetics

HbA1c Levels Fasting Blood Sugar Levels 2 hours After a Meal
Lower than 7% 80 to 130 mg/dL Under 180 mg/dL

 It is important to note that your doctor may prescribe different target blood sugar levels based on your health status and medical history.


Target Blood Sugar Levels in Pregnancy

The American Diabetes Association and the National Institutes of Health (NIH), USA recommend the following blood sugar level targets for most pregnant women with pre-existing diabetes (Type 1 or Type 2) or gestational diabetes.

Target Levels for Pregnant Women HbA1c Levels Fasting Blood Sugar Levels 1 hour After a Meal 2 hours After a Meal
Lower than 6.5% 95 mg/dL or lower 140 mg/dL or lower 120 mg/dL or lower


Normal Blood Sugar Levels in Children

The normal blood sugar levels in healthy children are the same as in healthy adults.


 Normal Blood Sugar in Children Fasting Blood Sugar Levels 2 hours After a Meal
70 to 100 mg/dL Under 140 mg/dL


The following table represents the target blood sugar levels in children and adolescents with diabetes, as recommended by the National Institutes of Health and the Central Council for Indian Medicine (CCIM):

Age (Years) Pre-prandial (Before a Meal) Post-prandial (After a meal) & at Bedtime
Younger than 6 Years 100 to 180 mg/dL 110 to 200 mg/dL
6 to 12 Years 90 to 180 mg/dL 100 to 180 mg/dL
13 to 19 Years 90 to 130 mg/dL 90 to 150 mg/dL


Abnormal Blood Sugar Levels

If your blood sugar level readings do not fall under the normal ranges, then they can fall under one of the below two categories:


1. Hypoglycemia

Hypoglycemia, also known as low blood sugar, is a condition in which your blood sugar levels drop below the normal range, generally defined as blood sugar levels lower than 70 mg/dL. 


A. Causes of Hypoglycemia:

Low blood sugar can be caused by a variety of factors including:

  • Insulin or oral diabetes medications
  • Missed or delayed meals
  • Excessive alcohol consumption
  • Increased physical activity or exercise
  • Certain medical conditions such as liver or kidney disease, tumors, hormonal disorders, etc.


B. Signs and Symptoms of Hypoglycemia:

Common symptoms of low blood sugar levels include: 

  • Irregular or fast heartbeat
  • Headache
  • Color draining from the skin 
  • Shakiness
  • Anxiety
  • Sweating 
  • Irritability 
  • Hunger 
  • Nausea 
  • Fatigue
  • Lightheadedness
  • Difficulty in concentrating
  • Tingling or numbness in the lips, tongue, or cheeks


The symptoms of hypoglycemia may vary from person to person, and some people may not even experience any symptoms, which is known as hypoglycemia unawareness.

Don’t have time to read? Here’s everything you need to know about Hypoglycemia in 5 mins.

C. Treatment of Hypoglycemia

Treatment for low blood sugar typically involves consuming a fast-acting source of glucose, such as fruit juice, table sugar, honey, candies or a glucose gel. In some cases, a complex carbohydrate such as crackers or bread may be consumed after a fast-acting carbohydrate in order to prevent hyperglycemia. If the person is unconscious or having seizures, a glucagon injection may be given. 


It is important to follow up with a longer-acting source of glucose, such as a meal, to prevent the recurrence of hypoglycemia. 

If you experience recurrent hypoglycemia, work with your to identify and address the underlying cause.

D. Complications of Hypoglycemia

Hypoglycemia can lead to a variety of complications, including:

  • Neurological symptoms: These can range from confusion and irritability in mild cases of hypoglycemia, to seizures and loss of consciousness in severe cases.
  • Cognitive impairment: Low blood sugar levels can affect cognitive function, making it difficult to think clearly or make decisions.
  • Motor impairment: Hypoglycemia can cause tremors (shaking), weakness, and difficulty coordinating movements.
  • Cardiovascular complications: Low blood sugar levels can cause an increase in heart rate and blood pressure, which can lead to palpitations, chest pain, and even heart attack.
  • Psychological complications: Hypoglycemia can cause anxiety, depression, and mood swings.
  • Injuries: Hypoglycemia can cause dizziness and fainting, and the resulting falls or motor impairment can lead to mild to severe injuries.
  • Diabetic coma: Dangerously low blood sugar levels can lead to loss of consciousness and a coma, which is a medical emergency that requires immediate hospitalization. 

It is important to work with your doctor to manage hypoglycemia, in order to prevent these complications from occurring.

2. Hyperglycemia

Hyperglycemia is the term used to refer to high blood sugar levels or blood glucose levels that are over the normal range.


A. Causes of Hyperglycemia:

High blood sugar can be caused by a variety of factors, including:

  • Not taking diabetes medications as prescribed or taking an insufficient dosage of insulin 
  • Certain medications, such as corticosteroids or diuretics
  • Stress, such as from an infection or injury
  • Eating too much or consuming too many carbohydrates
  • Not getting enough physical activity
  • Hormonal imbalances, such as in Cushing’s Syndrome or Hyperthyroidism.


B. Signs and Symptoms of Hyperglycemia:

The symptoms of hyperglycemia can include:

In severe cases, hyperglycemia can lead to ketoacidosis, a condition that can be life-threatening if left untreated.


Diabetic Ketoacidosis (DKA) occurs when your body produces very little insulin and as such is unable to use the glucose in your blood to generate energy. Because of this, your body starts breaking down fat to use it as fuel. Your liver processes these fats and turns them into ketones. 

The presence of too many ketones in your blood can turn it acidic and cause symptoms like:

  • Fruity-scented breath
  • Vomiting
  • Dry skin or mouth
  • Abdominal pain
  • Flushing
  • Headache
  • Muscle stiffness
  • Extreme fatigue


If you suspect that you may be experiencing DKA, it is important to seek immediate medical attention. 

C. Treatment of Hyperglycemia

In the long run, hyperglycemia is treated through a combination of lifestyle changes and medication. The main goal of treatment is to bring blood sugar levels back to a normal range and prevent complications.

Lifestyle changes that can help manage hyperglycemia include:

  • Eating a healthy, balanced diet
  • Exercising regularly
  • Maintaining a healthy weight
  • Monitoring blood sugar levels regularly.


Immediate treatment for hyperglycemia includes drinking more water, taking prescribed diabetic medications or insulin, or exercising. Avoid exercising if your ketone levels are high. If your blood sugar levels do not come back to normal despite these measures, contact your doctor immediately.


D. Complications of Hyperglycemia:

High blood sugar levels can lead to several serious complications if left untreated. These include:

  • Recurrent infections, including frequent colds, respiratory infections, urinary tract infections, yeast infections, etc., due to lowered immunity.
  • Slow healing wounds, that could lead to complications like diabetic foot.
  • Diabetic retinopathy, a condition that damages the blood vessels in the retina, potentially leading to blindness.
  • Nephropathy, a condition that damages the blood vessels in the kidneys, potentially leading to kidney failure.
  • Neuropathy, a condition that damages the nerves, leading to numbness, tingling, and pain in the extremities.
  • Cardiovascular disease, which can damage the blood vessels connected to the heart and lead to conditions like heart attack, stroke, heart failure, etc.


Thus, it is important that you closely monitor your blood sugar levels and work with your doctor to manage the condition better and prevent these complications.

How Can You Maintain Normal Blood Sugar Levels?

Many factors in your life can have an effect on your blood sugar levels. You can ensure your blood sugar levels remain normal by adopting the following measures: 

1. Eating a balanced diet

Your diet has a major impact on your blood sugar levels, and thus plays a key role in managing them. Foods that contain added sugars, simple carbohydrates, high saturated fat content, etc., can worsen your blood sugar control. 

Include more fresh fruits and vegetables, protein, fiber, and foods with a low glycemic index to your diet, as these foods can help keep your blood glucose levels stable.

2. Regular physical activity & exercise

Regular physical activity can help maintain normal blood sugar levels by increasing insulin sensitivity, which means that your cells are more responsive to insulin and are, therefore, able to use glucose more efficiently. 

Exercise causes your muscles to take up the excess glucose in your blood to provide your body with energy, which in turn lowers and stabilizes your blood sugar levels. At least 30 minutes of moderate exercise daily can help you lower your risks of diabetic complications. 


3. Maintaining a healthy weight

Being overweight or obese can make your cells less sensitive to insulin, which can lead to higher blood sugar levels. Excess fat in your body could also cause low-grade inflammation in your body, which can make your glycemic control worse. Losing even a small amount of weight can improve insulin sensitivity in your cells, which can help lower blood sugar levels.

4. Monitoring blood sugar levels regularly

The goal of diabetes management is to bring your blood glucose levels back down to a relatively normal range where it does not cause any complications. Hence monitoring and recording your blood glucose levels can help your doctor devise your treatment plan accordingly.

Regular monitoring can also help you identify patterns in your blood sugar levels, i.e. it helps you analyze how your diet and physical activity affect your blood sugar levels. This can help you make better lifestyle choices that can help you achieve normal blood glucose levels. 

5. Managing stress

When you are under stress, your body releases a hormone called cortisol. Chronically high cortisol levels can cause a spike in your blood glucose levels, as cortisol interferes with the functioning of insulin and promotes glucose production in the body. 

Long-term stress can also lead to unhealthy coping mechanisms like binge or stress-eating, lack of motivation to exercise, excessive alcohol consumption, smoking, etc., which can worsen your diabetes.

6. Sleeping well

A good night’s rest is key to regulating the production of the stress hormone cortisol and hunger hormone ghrelin in your body. Most experts recommend getting at least 7 hours of sleep every night for optimal health. 

When you sleep for less than 7 hours, it can result in your body producing more cortisol and ghrelin, which can raise your blood sugar levels and make you more hungry, respectively. This results in high blood sugar levels, which can then disrupt your sleep cycle, and lead to a vicious circle of lost sleep and poor glycemic control.


When to See a Doctor?

Consult your doctor if your recent blood sugar level readings are out of the normal range. Seek immediate medical attention if you are experiencing symptoms of hypoglycemia, hyperglycemia or diabetic ketoacidosis.


Don’t Have Time To Read?

  • Diabetes mellitus is a condition which results in high blood sugar levels, either due to insufficient insulin production in the body, or due to insulin resistance in the cells.
  • The three most common types of diabetes mellitus are Type 1 Diabetes, Type 2 Diabetes and Gestational Diabetes. Prediabetes is not a type of diabetes, but a precursor to Type 2 Diabetes.
  • High blood sugar levels in Type 1 Diabetes are caused by the destruction of insulin-producing cells in the pancreas.
  • High blood sugar levels in Type 2 Diabetes are caused by insulin resistance, where your cells are unable to effectively utilize the insulin produced in the body.
  • Blood sugar levels can be monitored with lab tests or at-home testing. Lab tests for blood sugar monitoring include fasting sugar levels test, post-prandial (after meal) sugar levels test, random sugar levels test and glycosylated hemoglobin (HbA1c) test.
  • You can monitor your blood glucose levels at home using devices like glucometers, flash blood glucose monitors and continuous glucose monitors.
  • Normal blood sugar levels in healthy adults differ from those in children and pregnant women.
  • Lower than normal blood sugar levels, or hypoglycemia, can cause symptoms like paleness, shakiness, hunger, headaches, tingling of face, dizziness, fainting, etc.
  • Severe hypoglycemia can cause complications like loss of consciousness, seizures and diabetic coma if left untreated.
  • Hypoglycemia can be treated by consuming fast-acting carbohydrates or sugary foods like candies, fruit juices, table sugar, honey, glucagon gel, etc.
  • Higher than normal blood sugar levels, or hyperglycemia, can cause symptoms like excessive thirst, frequent urination, blurred vision, dry mouth, etc.
  • Severe hyperglycemia can cause complications like frequent infections, slow wound healing, eye damage, kidney damage, heart disease, nerve damage, etc.
  • Long-term treatment of hyperglycemia includes measures like oral medications, insulin and lifestyle changes.
  • Short-term treatment of hyperglycemia includes taking prescribed medication or insulin, drinking more water, and exercising.
  • If you have diabetes, maintaining normal blood sugar levels can help lower your risk of developing associated complications.
  • You can maintain normal blood sugar levels by eating a balanced diet, exercising regularly, maintaining a healthy weight, monitoring blood sugar levels frequently, managing stress effectively and getting adequate sleep every night. 
  • Use the Phable Care App to consult India’s leading diabetologists, order medicines, book lab tests, integrate blood sugar monitoring and other devices to get real-time remote care from the comfort of your home. Also, check out our Diabetes Management program which provides ‎360º care. Let’s treat diabetes together.