A Complete Chart of the Normal Blood Sugar Range for Adults

17 Sep 2025 By Marisol S. Lance, D.O.

A Complete Chart of the Normal Blood Sugar Range for Adults

Understanding your blood sugar levels is crucial for maintaining optimal health and preventing diabetes-related complications. Blood glucose, often called blood sugar, is the main sugar found in your blood and comes from the food you eat. It’s your body's primary source of energy. Maintaining a healthy range is vital, but what exactly constitutes "normal"? This comprehensive guide provides a detailed chart and explains everything you need to know about the normal blood sugar range for adults, including factors that can affect it and when to seek medical advice.

What is Blood Sugar and Why Does It Matter?

Blood sugar refers to the concentration of glucose in your blood. Glucose is essential because it fuels your body's cells, providing the energy needed to function. The hormone insulin, produced by the pancreas, helps glucose from food get into cells to be used for energy.

Maintaining balanced blood sugar levels is crucial because:

Energy Production: Glucose fuels the body's cells.
Organ Function: Consistent blood sugar levels are essential for the proper functioning of organs like the brain, heart, and kidneys.
Diabetes Prevention: Chronically high blood sugar can lead to insulin resistance and, eventually, type 2 diabetes.

The body has intricate mechanisms to keep blood sugar levels within a narrow range. However, factors like diet, physical activity, stress, and certain medical conditions can disrupt this balance.

Normal Blood Sugar Levels Chart for Adults

Here's a detailed chart outlining the normal blood sugar range for adults without diabetes, as well as target ranges for those with diabetes, according to the American Diabetes Association (ADA). Note that these values are general guidelines, and your doctor may set different goals based on your individual health needs.

| Measurement | Normal (Non-Diabetic) | Target Range for Diabetics | | -------------------------------------------- | ------------------------------- | ---------------------------------- | | Fasting Blood Sugar (mg/dL) | 70-99 | 80-130 | | 2-Hour Postprandial (After Eating) (mg/dL) | Less than 140 | Less than 180 | | HbA1c (%) | Less than 5.7% | Less than 7.0% | Recognizing Severe Hypoglycemia A Guide For Persons With Diabetes

Key Definitions:

Fasting Blood Sugar: Blood sugar level measured after at least 8 hours of fasting (no food or drinks except water).
2-Hour Postprandial: Blood sugar level measured 2 hours after the start of a meal.
HbA1c: Glycated hemoglobin; a blood test that reflects your average blood sugar levels over the past 2-3 months.

Factors That Can Affect Blood Sugar Levels

Several factors can influence your blood sugar levels, causing them to fluctuate throughout the day. Understanding these factors can help you manage your blood sugar more effectively. Understanding Your Fasting Blood Glucose What It Is And Why It Matters

Diet:
- High-Carbohydrate Foods: Foods like bread, pasta, rice, and sugary drinks can cause a rapid increase in blood sugar levels.
- Processed Foods: Often high in sugar, unhealthy fats, and refined carbohydrates, which can negatively affect blood sugar control.
- Fiber: Fiber-rich foods like vegetables, fruits, and whole grains can help slow down the absorption of sugar, leading to more stable blood sugar levels.
Physical Activity:
- Exercise: Physical activity can lower blood sugar levels by increasing insulin sensitivity and helping cells use glucose for energy.
- Inactivity: Prolonged periods of inactivity can contribute to insulin resistance and higher blood sugar levels.
Stress:
- Hormonal Changes: Stress hormones like cortisol and adrenaline can raise blood sugar levels by stimulating the release of glucose from storage.
- Emotional Eating: Stress can sometimes lead to unhealthy eating habits, further impacting blood sugar levels.
Medications:
- Corticosteroids: Used to treat inflammation, can increase blood sugar levels.
- Diuretics: Used to treat high blood pressure, can affect blood sugar levels.
- Certain Psychiatric Medications: Some antidepressants and antipsychotics can impact insulin sensitivity and blood sugar control.
Medical Conditions:
- Infections: Can cause a temporary increase in blood sugar levels.
- Pancreatitis: Inflammation of the pancreas can impair insulin production.
- Cushing's Syndrome: Causes the body to produce too much cortisol, leading to elevated blood sugar levels.
Sleep:
- Lack of Sleep: Insufficient sleep can impair insulin sensitivity and increase blood sugar levels.
- Sleep Apnea: A sleep disorder characterized by pauses in breathing can also impact blood sugar control.

High Blood Sugar (Hyperglycemia): Causes, Symptoms, and Management

Hyperglycemia refers to high blood sugar levels, typically above 180 mg/dL. Chronic hyperglycemia can lead to serious health complications, including:

Heart Disease: Increases the risk of heart attack and stroke.
Kidney Disease: Can lead to kidney failure.
Nerve Damage (Neuropathy): Can cause numbness, tingling, and pain in the hands and feet.
Eye Damage (Retinopathy): Can lead to vision loss and blindness.

Common Causes of Hyperglycemia:

Overeating: Consuming more carbohydrates than your body can process.
Skipping Insulin or Diabetes Medications: Not taking medication as prescribed.
Infection or Illness: Stress on the body from illness can raise blood sugar levels.
Lack of Physical Activity: Not exercising regularly.

Symptoms of Hyperglycemia:

Frequent Urination: Especially at night.
Increased Thirst: Feeling unusually thirsty.
Blurred Vision: High blood sugar can affect the lens of the eye.
Fatigue: Feeling tired and weak.
Headaches: High blood sugar can cause headaches.

Managing Hyperglycemia:

Regular Monitoring: Check blood sugar levels frequently using a glucometer.
Diet Adjustments: Limit carbohydrate intake and focus on a balanced diet.
Exercise: Engage in regular physical activity to improve insulin sensitivity.
Medication: Take insulin or diabetes medications as prescribed by your doctor.
Stay Hydrated: Drink plenty of water to help flush out excess sugar.

Low Blood Sugar (Hypoglycemia): Causes, Symptoms, and Management

Hypoglycemia refers to low blood sugar levels, typically below 70 mg/dL. Hypoglycemia can be dangerous and requires prompt treatment.

Common Causes of Hypoglycemia:

Taking Too Much Insulin or Diabetes Medication: Overmedication can cause blood sugar to drop too low.
Skipping Meals: Not eating regularly, especially if taking insulin.
Intense Exercise: Exercising without sufficient carbohydrate intake.
Alcohol Consumption: Can interfere with the liver's ability to release glucose.

Symptoms of Hypoglycemia:

Shakiness: Feeling shaky or trembling.
Sweating: Breaking out in a cold sweat.
Dizziness: Feeling lightheaded or dizzy.
Confusion: Difficulty thinking clearly.
Irritability: Feeling anxious or irritable.
Rapid Heartbeat: Increased heart rate.
Hunger: Feeling intensely hungry.
Blurred Vision: Similar to hyperglycemia, low blood sugar can affect vision.

Managing Hypoglycemia:

Follow the "15-15 Rule":
1. Consume 15 grams of fast-acting carbohydrates (e.g., glucose tablets, fruit juice, regular soda).
2. Wait 15 minutes and check blood sugar levels again.
3. If blood sugar is still below 70 mg/dL, repeat steps 1 and 2.
Once blood sugar is above 70 mg/dL, eat a snack or meal to prevent it from dropping again.
Carry a Source of Fast-Acting Carbohydrates: Always have glucose tablets, juice, or hard candy on hand.
Wear a Medical Alert Bracelet: To inform others about your condition in case of an emergency.

The Role of HbA1c in Monitoring Blood Sugar Levels

HbA1c, also known as glycated hemoglobin, is a blood test that measures your average blood sugar levels over the past 2-3 months. Unlike a fasting blood sugar test, which provides a snapshot of your blood sugar at a single point in time, HbA1c gives a broader picture of your blood sugar control. Are Your Blood Sugar Levels A Warning Sign For Pre Diabetes

Interpreting HbA1c Results:

Normal: Less than 5.7%
Prediabetes: 5.7% to 6.4%
Diabetes: 6.5% or higher

The HbA1c test is particularly useful for:

Diagnosing Diabetes: HbA1c can be used to diagnose type 2 diabetes.
Monitoring Diabetes Management: It helps individuals with diabetes assess how well their blood sugar is controlled over time.
Adjusting Treatment Plans: Healthcare providers use HbA1c results to adjust medication, diet, and exercise plans.

Frequency of HbA1c Testing:

Individuals with Diabetes: At least twice a year, or more frequently if blood sugar control is not stable.
Individuals with Prediabetes: Annually, or more frequently if there are risk factors for developing diabetes.
Individuals without Diabetes or Prediabetes: As part of routine health checkups, particularly for those with risk factors for diabetes.

When to See a Doctor

While understanding normal blood sugar ranges and managing fluctuations can be done at home, certain situations warrant medical attention. You should consult a doctor if:

You Experience Frequent Episodes of Hyperglycemia or Hypoglycemia: Despite making lifestyle adjustments, your blood sugar levels remain consistently high or low.
You Have Symptoms of Diabetes: Increased thirst, frequent urination, unexplained weight loss, blurred vision, or slow-healing sores.
You Have Risk Factors for Diabetes: Family history of diabetes, obesity, high blood pressure, or high cholesterol.
You Are Pregnant: Gestational diabetes requires careful monitoring and management to ensure a healthy pregnancy.
You Are Planning to Start an Exercise Program: To determine if any adjustments to medication or diet are needed.
You Are Considering Using Herbal Supplements or Alternative Therapies: To ensure they are safe and won't interact with your medications.

Practical Tips for Maintaining Healthy Blood Sugar Levels

Maintaining stable blood sugar levels is a continuous effort that involves adopting healthy habits and making informed choices. Here are some practical tips to help you manage your blood sugar:

Follow a Balanced Diet:
- Focus on Whole Foods: Emphasize fruits, vegetables, whole grains, lean proteins, and healthy fats.
- Limit Processed Foods: Reduce your intake of sugary drinks, refined carbohydrates, and high-fat foods.
- Control Portion Sizes: Avoid overeating by using smaller plates and measuring food portions.
- Eat Regularly: Avoid skipping meals to prevent blood sugar fluctuations.
Engage in Regular Physical Activity:
- Aim for at Least 150 Minutes of Moderate-Intensity Exercise per Week: This could include brisk walking, cycling, swimming, or dancing.
- Incorporate Strength Training: Lift weights or use resistance bands to build muscle mass, which can improve insulin sensitivity.
- Stay Active Throughout the Day: Take short breaks from sitting to walk around or do some simple exercises.
Monitor Your Blood Sugar Regularly:
- Use a Glucometer: Check your blood sugar levels as directed by your doctor, especially if you have diabetes.
- Keep a Log: Record your blood sugar readings, along with information about your meals, activities, and medications.
- Share Your Results with Your Doctor: Discuss your blood sugar trends with your healthcare provider to make any necessary adjustments to your treatment plan.
Manage Stress:
- Practice Relaxation Techniques: Try meditation, deep breathing exercises, or yoga to reduce stress.
- Get Enough Sleep: Aim for 7-8 hours of quality sleep per night to improve insulin sensitivity.
- Engage in Enjoyable Activities: Make time for hobbies and activities that you find relaxing and enjoyable.
Stay Hydrated:
- Drink Plenty of Water: Water helps flush out excess sugar and keeps your body functioning properly.
- Avoid Sugary Drinks: Limit your intake of soda, juice, and sweetened beverages.
Limit Alcohol Consumption:
- Drink in Moderation: If you choose to drink alcohol, do so in moderation (up to one drink per day for women and up to two drinks per day for men).
- Eat Food While Drinking: Alcohol can lower blood sugar levels, so eat something while drinking to prevent hypoglycemia.
- Monitor Your Blood Sugar After Drinking: Check your blood sugar levels to see how alcohol affects you.

Conclusion

Understanding and maintaining a normal blood sugar range is essential for overall health and well-being. By being aware of the factors that can affect your blood sugar levels and taking proactive steps to manage them, you can reduce your risk of developing diabetes and related complications. Remember to consult with your healthcare provider for personalized advice and guidance based on your individual needs and medical history. This comprehensive guide provides a strong foundation for taking control of your blood sugar and ensuring a healthier future.