What Are Normal Blood Sugar Levels? A Guide with a Blood Sugar Chart

18 Sep 2025 By Ty S. Diwan, M.D.

What Are Normal Blood Sugar Levels? A Guide with a Blood Sugar Chart

Maintaining optimal blood sugar levels is vital for overall health. Blood sugar, or glucose, is the primary source of energy for our bodies. When blood sugar levels are consistently too high or too low, it can lead to serious health complications, including diabetes. Understanding what constitutes a normal range and how to monitor your blood sugar can help you make informed decisions about your health and lifestyle. This guide provides comprehensive information on normal blood sugar levels, factors affecting these levels, monitoring methods, and a handy blood sugar chart for quick reference.

Why Monitoring Blood Sugar Levels Is Important

Monitoring your blood sugar levels is essential for several reasons:

Early Detection of Diabetes: Regular monitoring can help identify prediabetes or diabetes early, allowing for timely intervention and management.
Diabetes Management: For individuals with diabetes, monitoring helps track the effectiveness of medication, diet, and exercise in maintaining blood sugar levels within the target range.
Prevention of Complications: Keeping blood sugar levels in a normal range can prevent or delay long-term complications of diabetes, such as heart disease, kidney disease, nerve damage, and vision problems.
Personalized Health Management: Monitoring provides valuable insights into how different foods, activities, and stress levels affect your blood sugar, enabling you to make personalized adjustments to your lifestyle.

Factors Affecting Blood Sugar Levels

Several factors can influence blood sugar levels, causing them to fluctuate throughout the day. These include:

Food Intake: The type and amount of food you eat significantly affect your blood sugar. Carbohydrates are broken down into glucose, raising blood sugar levels.
Physical Activity: Exercise can lower blood sugar levels as muscles use glucose for energy.
Stress: Stress hormones, such as cortisol and adrenaline, can raise blood sugar levels.
Medications: Certain medications, including steroids, diuretics, and some antidepressants, can increase blood sugar levels. Conversely, diabetes medications are designed to lower blood sugar levels.
Illness: Infections and illnesses can cause blood sugar levels to rise due to the body's stress response.
Dehydration: Dehydration can concentrate blood sugar, leading to higher readings.
Menstrual Cycle: Hormonal changes during the menstrual cycle can affect blood sugar levels in women.
Time of Day: Blood sugar levels tend to be higher in the morning due to hormonal changes (the dawn phenomenon).

Understanding these factors can help you better manage your blood sugar levels and make informed lifestyle choices.

Understanding Normal Blood Sugar Levels: The Chart

What constitutes a "normal" blood sugar level? This can vary based on several factors, including whether you have diabetes, your age, and when you last ate. Generally, blood sugar levels are measured in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L).

Here's a blood sugar chart outlining the general target ranges for people with and without diabetes, as recommended by the American Diabetes Association:

Explanations of Key Terms in the Chart

Fasting Blood Sugar: This is your blood sugar level after not eating for at least eight hours, usually measured in the morning before breakfast.
2 Hours After Eating: This measures your blood sugar level two hours after the start of a meal. It helps assess how your body processes glucose from food.
A1C (Average over 3 Months): The A1C test provides an average of your blood sugar levels over the past three months. It reflects long-term blood sugar control.

Specific Scenarios and Target Ranges

Before Meals:
- For people without diabetes: 70-99 mg/dL (3.9-5.5 mmol/L)
- For people with diabetes: 80-130 mg/dL (4.4-7.2 mmol/L)
1-2 Hours After Meals:
- For people without diabetes: Less than 140 mg/dL (7.8 mmol/L)
- For people with diabetes: Less than 180 mg/dL (10.0 mmol/L)
Bedtime:
- For people with diabetes: 90-150 mg/dL (5.0-8.3 mmol/L)

Factors That Can Influence Target Ranges

It’s important to note that these target ranges may vary based on individual circumstances. Factors such as age, overall health, duration of diabetes, presence of other health conditions, and pregnancy can influence the optimal blood sugar target. Always consult with your healthcare provider to determine the best target range for you.

Blood Sugar Levels and Potential Health Conditions

Understanding the implications of different blood sugar levels is essential. Here’s a breakdown:

| Blood Sugar Level | Condition/Risk | Implications | | :----------------------- | :--------------------------- | :---------------------------------------------------------------------------------------------- | | Below 70 mg/dL (3.9 mmol/L) | Hypoglycemia | Can cause shakiness, sweating, confusion, and in severe cases, loss of consciousness. | | 100-125 mg/dL (5.6-6.9 mmol/L) | Prediabetes (Impaired Fasting Glucose) | Indicates a higher risk of developing type 2 diabetes and cardiovascular disease. | | 126 mg/dL or higher (7.0 mmol/L or higher) | Diabetes | Requires further evaluation and management to prevent complications. | | 140-199 mg/dL (7.8-11.0 mmol/L) 2 hours after eating | Prediabetes (Impaired Glucose Tolerance) | Indicates a higher risk of developing type 2 diabetes and cardiovascular disease. | | 200 mg/dL or higher (11.1 mmol/L or higher) 2 hours after eating | Diabetes | Requires further evaluation and management to prevent complications. | Easy Breakfasts For Excellent Blood Sugar Control All Morning

These values serve as a general guide. It is imperative to discuss any concerns about your blood sugar levels with a healthcare professional for accurate diagnosis and personalized management.

How to Monitor Your Blood Sugar Levels

Regular monitoring of blood sugar levels is a cornerstone of diabetes management and a valuable tool for maintaining overall health. There are several methods available for monitoring, each with its advantages and considerations.

1. Self-Monitoring of Blood Glucose (SMBG)

Self-Monitoring of Blood Glucose (SMBG) involves using a blood glucose meter to measure your blood sugar at home. Here's how it works:

Gather Your Supplies: You will need a blood glucose meter, test strips, a lancing device, and alcohol swabs.
Wash and Dry Your Hands: Ensure your hands are clean and dry to avoid inaccurate readings.
Prepare the Lancing Device: Insert a lancet into the lancing device.
Prick Your Finger: Use the lancing device to prick the side of your fingertip.
Apply Blood to the Test Strip: Gently squeeze your finger to obtain a small drop of blood and apply it to the test strip.
Insert the Test Strip into the Meter: The meter will display your blood sugar level within seconds.
Record Your Results: Keep a log of your readings, noting the date, time, and any relevant information, such as meals or activities.

Tips for Accurate SMBG:

Use Fresh Test Strips: Ensure your test strips are not expired, as expired strips can give inaccurate readings.
Calibrate Your Meter: Regularly calibrate your meter according to the manufacturer's instructions.
Store Test Strips Properly: Store test strips in a cool, dry place, away from direct sunlight.
Avoid Milking Your Finger: Milking your finger can dilute the blood sample, leading to inaccurate readings.
Clean Your Meter: Clean your meter regularly to remove any residue that could affect accuracy.

2. Continuous Glucose Monitoring (CGM)

Continuous Glucose Monitoring (CGM) involves wearing a small device that continuously tracks your blood sugar levels throughout the day and night. A small sensor inserted under the skin measures glucose levels in interstitial fluid (the fluid surrounding cells). The sensor transmits data to a receiver or smartphone, providing real-time blood sugar readings and trends.

Benefits of CGM:

Continuous Monitoring: CGM provides a continuous stream of blood sugar data, allowing you to see how your blood sugar changes in response to meals, exercise, and other factors.
Trend Alerts: CGM devices can alert you when your blood sugar is rising or falling too quickly, enabling you to take proactive steps to prevent highs and lows.
Improved Glucose Control: CGM can help improve overall glucose control by providing insights into patterns and trends that may not be apparent with SMBG.
Reduced Fingersticks: CGM reduces the need for frequent fingersticks, making it a more convenient option for many people.

Limitations of CGM:

Calibration: CGM devices require periodic calibration with fingerstick blood sugar readings.
Accuracy: CGM readings may lag behind fingerstick readings, especially during periods of rapid blood sugar change.
Cost: CGM systems can be expensive, and not all insurance plans cover the cost.

3. A1C Test

The A1C test measures your average blood sugar levels over the past three months. It provides a broader picture of your blood sugar control than daily blood sugar monitoring. The A1C test is typically performed in a healthcare setting and does not require fasting. What Is Postprandial Blood Sugar And How Can You Manage It

Interpreting A1C Results:

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

Choosing the Right Monitoring Method

The best monitoring method for you will depend on your individual needs, lifestyle, and preferences. SMBG is a cost-effective option for monitoring blood sugar levels at home, while CGM provides continuous data and trend alerts. The A1C test offers a long-term perspective on blood sugar control. Consult with your healthcare provider to determine the most appropriate monitoring method for you.

Tips for Maintaining Healthy Blood Sugar Levels

Maintaining healthy blood sugar levels requires a holistic approach that includes lifestyle modifications, dietary changes, and, if necessary, medication. Here are some effective tips for keeping your blood sugar in a healthy range:

1. Balanced Diet

A balanced diet is crucial for maintaining stable blood sugar levels. Focus on whole, unprocessed foods that are low in sugar and high in fiber.

Choose Complex Carbohydrates: Opt for whole grains, such as brown rice, quinoa, and whole-wheat bread, over refined carbohydrates, such as white bread and pastries. Complex carbohydrates are digested more slowly, leading to a more gradual rise in blood sugar levels.
Eat Plenty of Fiber: Fiber slows down the absorption of sugar, helping to prevent spikes in blood sugar levels. Good sources of fiber include fruits, vegetables, legumes, and whole grains.
Include Lean Protein: Protein helps stabilize blood sugar levels and promotes satiety. Choose lean sources of protein, such as chicken, fish, beans, and tofu.
Healthy Fats: Incorporate healthy fats, such as those found in avocados, nuts, seeds, and olive oil, into your diet. Healthy fats can improve insulin sensitivity and help regulate blood sugar levels.

2. Regular Exercise

Physical activity is an essential component of blood sugar management. Exercise helps lower blood sugar levels by increasing insulin sensitivity and using glucose for energy.

Aim for 30 Minutes of Moderate Exercise Daily: Engage in activities such as brisk walking, cycling, swimming, or dancing for at least 30 minutes most days of the week.
Incorporate Strength Training: Strength training can help build muscle mass, which improves glucose metabolism. Aim for strength training exercises at least two days per week.
Monitor Your Blood Sugar Before and After Exercise: Check your blood sugar levels before and after exercise to see how your body responds to activity. Adjust your diet or medication as needed.

3. Stay Hydrated

Dehydration can concentrate blood sugar, leading to higher readings. Drink plenty of water throughout the day to stay hydrated.

Aim for 8 Glasses of Water Daily: Drink at least eight glasses of water per day, or more if you are physically active or live in a hot climate.
Avoid Sugary Drinks: Limit your intake of sugary drinks, such as soda, juice, and sweetened beverages, as these can cause rapid spikes in blood sugar levels.

4. Manage Stress

Stress can raise blood sugar levels by triggering the release of stress hormones. Find healthy ways to manage stress, such as:

Practice Relaxation Techniques: Engage in activities such as meditation, yoga, deep breathing exercises, or mindfulness to reduce stress.
Get Enough Sleep: Aim for 7-8 hours of sleep per night to promote overall health and reduce stress.
Engage in Hobbies: Spend time doing things you enjoy, such as reading, gardening, or spending time with loved ones.

5. Limit Alcohol Intake

Alcohol can affect blood sugar levels in unpredictable ways. It can cause blood sugar to drop, especially if consumed on an empty stomach or in combination with diabetes medications. The Simple Guide To Normal Blood Sugar Levels By Age

Consume Alcohol in Moderation: If you choose to drink alcohol, do so in moderation. The American Diabetes Association recommends no more than one drink per day for women and no more than two drinks per day for men.
Eat Food When Drinking Alcohol: Always eat food when drinking alcohol to prevent blood sugar from dropping too low.
Check Your Blood Sugar After Drinking Alcohol: Monitor your blood sugar after drinking alcohol to see how it affects your levels.

6. Monitor Medication

If you take medications for diabetes, it's important to adhere to your prescribed regimen. Work closely with your healthcare provider to adjust your medication as needed based on your blood sugar levels and overall health.

7. Regular Check-Ups

Regular check-ups with your healthcare provider are essential for monitoring your blood sugar levels and overall health. Your doctor can perform A1C tests, assess your medication, and provide personalized advice for managing your blood sugar.

Final Thoughts

Understanding and maintaining normal blood sugar levels is essential for overall health and well-being. By understanding the factors that affect blood sugar levels, monitoring your levels regularly, and adopting healthy lifestyle habits, you can effectively manage your blood sugar and prevent or delay the onset of diabetes and its complications. Always consult with your healthcare provider for personalized advice and guidance on managing your blood sugar levels.