The Ultimate Blood Sugar Chart: Normal Levels for Adults with and without Diabetes

18 Sep 2025 By Chris M. Adams, M.D., Ph.D.

The Ultimate Blood Sugar Chart: Normal Levels for Adults with and without Diabetes

Understanding blood sugar levels is crucial for maintaining optimal health, especially for individuals with diabetes or those at risk. Monitoring your blood sugar helps manage energy levels, prevent complications, and make informed decisions about diet and lifestyle. This comprehensive guide provides a detailed blood sugar chart, explains normal levels for adults both with and without diabetes, and offers practical insights into managing your blood sugar effectively.

Why Monitoring Blood Sugar Is Essential

Blood sugar, or glucose, is the main sugar found in your blood, coming from the food you eat. It’s your body’s primary source of energy. Maintaining stable blood sugar levels is essential because consistently high or low levels can lead to severe health problems.

For Individuals Without Diabetes: Monitoring can help identify prediabetes, allowing for early intervention through lifestyle changes.
For Individuals With Diabetes: Regular monitoring is critical for managing the condition, adjusting medication, and preventing complications such as nerve damage, kidney disease, and heart problems.

Understanding your blood glucose levels enables proactive health management, empowering you to take necessary actions to maintain overall well-being.

Blood Sugar Chart: Target Ranges for Adults

Here is a comprehensive blood sugar chart providing target ranges for adults both with and without diabetes. These ranges are generally recommended, but always consult with your healthcare provider for personalized targets based on your individual health profile.

Key Terms:

Fasting Blood Sugar: Measured after at least 8 hours of not eating.
Postprandial Blood Sugar: Measured 1-2 hours after eating a meal.
HbA1c: A blood test that provides an average of blood sugar levels over the past 2-3 months.

Detailed Explanation of Each Range

1. Fasting Blood Sugar: For individuals without diabetes, a fasting blood glucose level should ideally be between 70-99 mg/dL. This range indicates that the body is effectively regulating blood sugar overnight and utilizing insulin properly. For those with diabetes, a target range of 80-130 mg/dL is commonly recommended. However, it's important to note that individual targets may vary based on age, overall health, and specific diabetes management plans.

2. Before a Meal: Similar to fasting blood sugar, the pre-meal target for those without diabetes is between 70-99 mg/dL. This range signifies that the body is prepared to handle the incoming glucose from food intake. For individuals with diabetes, the pre-meal target is also between 80-130 mg/dL, aiming to optimize blood sugar levels before the additional glucose load from the meal.

3. 1-2 Hours After Meal (Postprandial): The postprandial blood sugar level is a crucial indicator of how well the body processes glucose after a meal. For those without diabetes, the level should remain below 140 mg/dL. For individuals with diabetes, maintaining postprandial levels below 180 mg/dL is generally advised. Consistently high postprandial levels can indicate insulin resistance or insufficient insulin production, necessitating adjustments to diet, exercise, or medication.

4. HbA1c (Glycated Hemoglobin): The HbA1c test provides a comprehensive overview of average blood sugar levels over the past 2-3 months. This test is invaluable for long-term diabetes management. For individuals without diabetes, an HbA1c level of less than 5.7% is considered normal. For those with diabetes, the general target is less than 7.0%, although this can be further individualized based on a person's specific health circumstances and goals.

Normal Blood Sugar Levels for Adults Without Diabetes

For adults without diabetes, maintaining blood sugar levels within the normal range is crucial for overall health. Here are the generally accepted ranges:

Fasting: 70-99 mg/dL
Two Hours After Eating: Less than 140 mg/dL
A1C: Less than 5.7%

If your blood sugar levels consistently fall outside these ranges, it may indicate prediabetes or another underlying health issue, warranting further investigation and consultation with a healthcare provider. Feeling Shaky Key Low Blood Sugar Symptoms And What To Do Next

What Factors Can Affect Blood Sugar Levels in Non-Diabetics?

Even in the absence of diabetes, several factors can cause fluctuations in blood sugar levels:

Diet: High-carbohydrate foods and sugary drinks can cause a temporary spike in blood sugar.
Physical Activity: Exercise can lower blood sugar levels as your muscles use glucose for energy.
Stress: Stress hormones like cortisol can raise blood sugar levels.
Illness: Infections can temporarily increase blood sugar levels.
Medications: Certain medications, such as steroids, can affect blood sugar.

Understanding these factors and how they influence your blood sugar can help you make informed lifestyle choices to maintain stable levels.

Blood Sugar Levels for Adults with Diabetes

For individuals with diabetes, managing blood glucose levels within the target range is essential for preventing complications. However, target ranges can vary depending on individual factors such as age, overall health, and the type of diabetes (Type 1, Type 2, or Gestational).

General Targets for Adults with Diabetes:

Fasting: 80-130 mg/dL
Two Hours After Eating: Less than 180 mg/dL
A1C: Less than 7.0%

Factors Affecting Blood Sugar Levels in Diabetics

Managing blood sugar effectively requires a comprehensive understanding of the factors that influence glucose levels. For individuals with diabetes, these factors are particularly critical:

Dietary Intake: The type, amount, and timing of food consumption play a significant role in blood sugar management. High-carbohydrate foods, sugary beverages, and processed foods can cause rapid spikes in glucose levels. On the other hand, consuming a balanced diet with controlled portions of complex carbohydrates, lean proteins, and healthy fats can help stabilize blood sugar.
Physical Activity: Regular physical exercise is a cornerstone of diabetes management. When you engage in physical activity, your muscles utilize glucose for energy, leading to a reduction in blood sugar levels. Exercise also enhances insulin sensitivity, which helps the body use insulin more effectively. Both aerobic exercises (e.g., walking, jogging, swimming) and resistance training (e.g., weightlifting) offer significant benefits for blood sugar control.
Medication Adherence: For many individuals with diabetes, medication is essential to maintaining target glucose levels. This may include oral medications, insulin injections, or other injectable medications. Consistent and accurate adherence to the prescribed medication regimen is crucial. Factors such as timing, dosage, and technique (for insulin injections) can significantly impact blood sugar levels.
Stress Management: Stress triggers the release of hormones, such as cortisol and adrenaline, which can elevate blood sugar levels. For individuals with diabetes, learning and implementing effective stress management techniques is crucial for maintaining glucose control.
Illness and Infections: When the body is fighting off an illness or infection, it releases stress hormones to support the immune system. These hormones can also cause blood sugar levels to increase. Therefore, individuals with diabetes need to closely monitor their glucose levels during periods of illness and consult with their healthcare provider to adjust their medication or treatment plan as needed.
Hydration: Staying adequately hydrated is often overlooked but is a vital component of blood sugar management. Dehydration can lead to higher concentrations of glucose in the blood, exacerbating hyperglycemia (high blood sugar). Drinking sufficient water throughout the day helps the kidneys flush out excess glucose and maintain optimal blood sugar levels. A Beginner S Guide To Understanding Your Blood Sugar Range

Hypoglycemia vs. Hyperglycemia: Recognizing the Signs

Hypoglycemia (Low Blood Sugar):

Occurs when blood sugar levels drop too low, typically below 70 mg/dL. Symptoms can include:

Shakiness
Sweating
Dizziness
Confusion
Irritability
Rapid heartbeat

If you experience these symptoms, check your blood sugar and consume a quick-acting source of glucose (such as glucose tablets or fruit juice) to raise your levels. The Surprising Connection Between Insulin Resistance And A1C Levels

Hyperglycemia (High Blood Sugar):

Occurs when blood sugar levels are too high, generally above 180 mg/dL. Symptoms can include:

Frequent urination
Excessive thirst
Blurred vision
Fatigue
Headaches

If you experience these symptoms, check your blood sugar and follow your diabetes management plan, which may include adjusting medication, diet, or exercise.

Managing Hypoglycemia and Hyperglycemia

Managing Hypoglycemia

Immediate Action: If you suspect hypoglycemia, immediately check your blood sugar levels with a glucose meter. If the reading is below 70 mg/dL (3.9 mmol/L), take action to raise your blood sugar levels.
The 15-15 Rule: Consume 15 grams of fast-acting carbohydrates, such as:
- Glucose tablets (follow package instructions)
- 4 ounces (120 ml) of fruit juice or regular soda
- 1 tablespoon of honey or sugar
Recheck and Repeat: Wait 15 minutes, then recheck your blood sugar levels. If your blood sugar is still below 70 mg/dL (3.9 mmol/L), repeat the process by consuming another 15 grams of fast-acting carbohydrates.
Stable Levels: Once your blood sugar rises above 70 mg/dL (3.9 mmol/L), consume a longer-acting carbohydrate source, such as a small snack containing protein and complex carbohydrates (e.g., peanut butter on whole-grain crackers). This will help stabilize your blood sugar and prevent another drop.

Managing Hyperglycemia

Regular Monitoring: Use a blood glucose meter to regularly monitor your blood sugar levels. Pay attention to patterns and trends to better understand how different factors (e.g., food, activity, stress) affect your glucose levels.
Adjust Medication: If you frequently experience hyperglycemia, consult your healthcare provider or certified diabetes educator (CDE) to review and adjust your diabetes management plan. This may involve modifying the dosage or timing of your medications (oral agents or insulin) or switching to a different medication.
Hydration: Drink plenty of water to help flush out excess glucose from your system and maintain optimal blood sugar levels.
Regular Exercise: Incorporate regular physical activity into your routine to improve insulin sensitivity and lower blood sugar levels. Aim for at least 30 minutes of moderate-intensity exercise most days of the week. Always check with your doctor before starting a new exercise program.

Tools for Monitoring Blood Sugar

Blood Glucose Meter: A portable device used to measure the amount of glucose in a drop of blood.
Continuous Glucose Monitor (CGM): A device that continuously tracks glucose levels throughout the day and night, providing real-time data and alerts.
A1C Test: A blood test that measures average blood sugar levels over the past 2-3 months.

Choosing the Right Monitoring Method

Blood Glucose Meter: Ideal for routine checks and spot-checking blood sugar levels. Cost-effective and easy to use.
Continuous Glucose Monitor (CGM): Provides comprehensive data and insights into blood sugar patterns, helping you make more informed decisions about diet, exercise, and medication.
A1C Test: Used to assess long-term blood sugar control, providing a broader picture of your overall glucose management.

Practical Tips for Maintaining Healthy Blood Sugar Levels

Dietary Strategies

Eat Balanced Meals: Include a mix of complex carbohydrates, lean proteins, and healthy fats.
Control Portion Sizes: Avoid overeating, which can lead to blood sugar spikes.
Choose Low-Glycemic Foods: Opt for foods that have a minimal impact on blood sugar levels, such as whole grains, non-starchy vegetables, and legumes.

Lifestyle Adjustments

Regular Exercise: Aim for at least 30 minutes of moderate-intensity exercise most days of the week.
Stress Management: Practice relaxation techniques like deep breathing, meditation, or yoga.
Adequate Sleep: Aim for 7-9 hours of quality sleep per night to support hormonal balance and glucose regulation.

Regular Check-ups

Routine Screenings: If you have risk factors for diabetes, such as family history or obesity, get regular blood sugar screenings.
Professional Guidance: Work with a healthcare provider or certified diabetes educator (CDE) to develop a personalized management plan.

By understanding the blood sugar chart, recognizing the signs of high and low blood sugar, and adopting healthy lifestyle habits, you can effectively manage your blood sugar levels and maintain optimal health.