A Guide for Persons with Diabetes: Understanding Your Blood Sugar Level

02 Sep 2025

A Guide for Persons with Diabetes: Understanding Your Blood Sugar Level Diabetes is a chronic health condition affecting millions worldwide. At its co...

A Guide for Persons with Diabetes: Understanding Your Blood Sugar Level

Diabetes is a chronic health condition affecting millions worldwide. At its core, diabetes is about how your body uses glucose, the main type of sugar in your blood. For people living with diabetes, understanding blood sugar levels is essential for managing their condition effectively. This guide aims to provide a comprehensive overview of blood sugar levels, helping individuals with diabetes navigate the complexities of monitoring and maintaining their health.

Knowing your blood glucose levels enables informed decisions regarding diet, exercise, and medication, leading to better health outcomes and a higher quality of life. Let's explore the critical aspects of understanding and managing your blood sugar.

What are Blood Sugar Levels?

Blood sugar levels, also known as blood glucose levels, indicate the concentration of glucose in your blood. Glucose comes from the food you eat and serves as the primary energy source for your body's cells. In healthy individuals, the hormone insulin, produced by the pancreas, helps glucose move from the bloodstream into cells to be used for energy.

In people with diabetes, this process is disrupted. In Type 1 diabetes, the body doesn't produce insulin. In Type 2 diabetes, the body either doesn't produce enough insulin or the cells become resistant to it. As a result, glucose builds up in the blood, leading to high blood sugar levels, also known as hyperglycemia. Conversely, when blood sugar levels drop too low, it's known as hypoglycemia.

Understanding Blood Sugar Measurement Units

Blood sugar levels are typically measured in one of two units:

  • Milligrams per deciliter (mg/dL): Primarily used in the United States.
  • Millimoles per liter (mmol/L): Commonly used in most other countries, including Canada, the UK, and Europe.

To convert mg/dL to mmol/L, divide the mg/dL value by 18. For example, 100 mg/dL is approximately 5.5 mmol/L.

| Measurement | mg/dL | mmol/L | |-------------------------|-------|--------| | Common US Unit | 100 | 5.5 | | International Unit | 18 | 1.0 |

Understanding these units and being able to interpret your blood sugar readings in either format is crucial for managing your diabetes effectively, especially when traveling or interacting with healthcare providers from different regions.

Why Monitoring Blood Sugar is Important

Regular monitoring of blood sugar levels is paramount for individuals with diabetes because it provides invaluable insights into how well your body is managing glucose. It's akin to regularly checking the fuel gauge in your car; without this knowledge, you risk running out of gas or overfilling the tank. Here's a breakdown of why it is crucial:

Related reading: Could You Have Hypoglycemia The Warning Signs Of Low Blood Sugar

  • Effective Diabetes Management: Blood sugar monitoring helps you understand how food, exercise, stress, and medications affect your glucose levels. This insight allows you to make informed decisions about adjusting your diet, physical activity, or medication dosages in consultation with your healthcare provider.
  • Preventing Complications: Consistent high blood sugar levels can lead to numerous long-term complications, including nerve damage (neuropathy), kidney damage (nephropathy), eye damage (retinopathy), cardiovascular diseases, and foot problems. Regular monitoring enables you to identify trends and patterns that help prevent these complications.
  • Avoiding Hypoglycemia: Low blood sugar (hypoglycemia) can occur from taking too much insulin, skipping meals, or exercising vigorously without adjusting medication or food intake. Monitoring helps detect and prevent these potentially dangerous drops in blood sugar.
  • Personalized Treatment Plans: By regularly tracking your blood sugar levels, you and your healthcare team can develop a more personalized treatment plan that addresses your specific needs and lifestyle. This leads to better glycemic control and overall well-being.
  • Enhanced Awareness: Regular monitoring increases your awareness of how different factors affect your diabetes. This heightened awareness empowers you to take proactive steps in managing your condition effectively.

| Importance | Explanation | |----------------------------|--------------------------------------------------------------------------------------------------------------------------| | Effective Management | Allows informed decisions about diet, exercise, and medication. | | Preventing Complications| Helps avoid long-term nerve, kidney, eye, and cardiovascular damage. | | Avoiding Hypoglycemia | Detects and prevents dangerous drops in blood sugar. | | Personalized Treatment | Enables a customized treatment plan tailored to individual needs and lifestyle. | | Enhanced Awareness | Increases understanding and proactive management of diabetes. |

Target Blood Sugar Levels

Target blood sugar levels can vary depending on individual factors such as age, type of diabetes, overall health, and specific treatment plans. However, general guidelines are often used. These ranges are typically defined for pre-meal (fasting) and post-meal (1-2 hours after eating) readings. The American Diabetes Association (ADA) provides the following recommendations:

  • Fasting Blood Sugar: 80-130 mg/dL (4.4-7.2 mmol/L)
  • Postprandial (After Meal): Less than 180 mg/dL (10.0 mmol/L)

It's important to note that these are general targets and should be individualized by your healthcare provider. Pregnant women with diabetes may have tighter targets to ensure the health of both mother and baby. Some individuals, particularly older adults, may have less stringent targets to reduce the risk of hypoglycemia.

| Time of Day | ADA Target (mg/dL) | ADA Target (mmol/L) | |------------------|--------------------|---------------------| | Fasting | 80-130 | 4.4-7.2 | | Postprandial | Less than 180 | Less than 10.0 |

Hemoglobin A1c (HbA1c)

In addition to daily blood sugar monitoring, the Hemoglobin A1c (HbA1c) test provides an average of your blood sugar levels over the past 2-3 months. The ADA recommends an HbA1c target of less than 7% for many non-pregnant adults with diabetes.

  • HbA1c: Less than 7%

HbA1c correlates with average blood glucose levels as follows:

| A1c (%) | eAG (mg/dL) | eAG (mmol/L) | |---------|-------------|--------------| | 6 | 126 | 7.0 | | 7 | 154 | 8.6 | | 8 | 183 | 10.1 | | 9 | 212 | 11.8 | | 10 | 240 | 13.4 |

Discuss your target blood sugar levels and HbA1c with your healthcare provider to personalize your diabetes management plan.

Methods for Checking Blood Sugar

There are several methods available for checking blood sugar, each with its own advantages and drawbacks.

1. Blood Glucose Meters (Glucometers)

Blood glucose meters are the most common method for monitoring blood sugar levels at home. They require a small blood sample, typically obtained by pricking your fingertip with a lancet.

  • How it Works:

    1. Wash and dry your hands.
    2. Insert a test strip into the meter.
    3. Use the lancet to prick the side of your fingertip.
    4. Gently squeeze a drop of blood onto the test strip.
    5. Wait for the meter to display the blood sugar reading.
    6. Advantages:
    7. Relatively inexpensive.
    8. Portable and easy to use.
    9. Provides immediate results.
    10. Disadvantages:
    11. Requires finger pricks.
    12. Test strips and lancets need to be purchased regularly.
    13. Can be affected by user error (e.g., improper technique, expired strips).

2. Continuous Glucose Monitoring (CGM)

Continuous Glucose Monitoring (CGM) systems use a small sensor inserted under the skin to measure glucose levels in the interstitial fluid (the fluid surrounding cells). The sensor is connected to a transmitter that sends glucose readings to a receiver or smartphone app.

  • How it Works:

    1. Insert the sensor under the skin (usually on the abdomen or arm).
    2. The sensor measures glucose levels continuously, typically every 5-15 minutes.
    3. Readings are transmitted to a receiver or smartphone.
    4. Advantages:
    5. Provides real-time glucose readings.
    6. Shows glucose trends (i.e., rising, falling, or stable).
    7. Can alert you to highs and lows.
    8. Reduces the need for frequent finger pricks.
    9. Disadvantages:
    10. More expensive than blood glucose meters.
    11. Requires calibration with finger prick blood sugar readings.
    12. May have a lag time between interstitial glucose and blood glucose levels.
    13. Some users may experience skin irritation at the sensor insertion site.

3. Flash Glucose Monitoring (FGM)

Flash Glucose Monitoring (FGM), such as the FreeStyle Libre system, involves wearing a sensor on the upper arm that measures glucose levels in the interstitial fluid. Unlike CGM, FGM does not automatically transmit glucose readings.

  • How it Works:

    1. Apply the sensor to the upper arm.
    2. Scan the sensor with a reader device or smartphone to obtain a glucose reading.
    3. The reader stores glucose data over time, allowing you to see trends.
    4. Advantages:
    5. Reduces the need for routine finger pricks (finger pricks are only needed if symptoms don’t match readings).
    6. Provides glucose trends.
    7. Relatively easy to use.
    8. Disadvantages:
    9. Requires scanning to obtain readings.
    10. May have a lag time between interstitial glucose and blood glucose levels.
    11. Sensor cost can be a barrier for some users.

| Method | Description | Advantages | Disadvantages | |------------------------|---------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------| | Blood Glucose Meter| Uses a blood sample to measure glucose levels. | Inexpensive, portable, provides immediate results. | Requires finger pricks, needs regular purchases of strips and lancets, prone to user error. | | CGM | Measures glucose levels continuously via a sensor under the skin. | Provides real-time readings and trends, alerts for highs and lows, reduces the need for frequent finger pricks. | More expensive, requires calibration, potential lag time, possible skin irritation. | | FGM | Measures glucose levels in interstitial fluid via a sensor, requires scanning for readings. | Reduces routine finger pricks, provides glucose trends, easy to use. | Requires scanning, potential lag time, sensor cost. |

Related reading: The Link Between Insulin And Blood Sugar A Simple Explanation

Managing High Blood Sugar (Hyperglycemia)

Hyperglycemia, or high blood sugar, occurs when glucose levels in the blood are too high. This can happen for several reasons, including:

  • Eating more carbohydrates than usual
  • Missing a dose of diabetes medication
  • Illness or infection
  • Stress
  • Inactivity

Symptoms of Hyperglycemia

  • Frequent urination
  • Increased thirst
  • Blurred vision
  • Fatigue
  • Headache

Steps to Take When Blood Sugar is High

  1. Check Your Blood Sugar: Verify that your blood sugar is indeed high.
  2. Take Medication as Prescribed: If you take insulin or other diabetes medications, administer your prescribed dose.
  3. Drink Water: Staying hydrated can help flush excess glucose from your body.
  4. Exercise: Light physical activity can help lower blood sugar levels.
  5. Adjust Diet: Avoid sugary drinks and snacks.
  6. Monitor Regularly: Check your blood sugar more frequently to ensure it is trending down.
  7. Contact Your Healthcare Provider: If your blood sugar remains high despite these measures or if you experience severe symptoms, contact your healthcare provider.

Managing Low Blood Sugar (Hypoglycemia)

Hypoglycemia, or low blood sugar, occurs when glucose levels in the blood are too low. This can happen for several reasons, including:

  • Taking too much insulin or other diabetes medications
  • Skipping meals or snacks
  • Exercising without adjusting medication or food intake
  • Drinking alcohol

Symptoms of Hypoglycemia

  • Shakiness
  • Sweating
  • Dizziness
  • Confusion
  • Irritability
  • Hunger
  • Rapid heartbeat
  • Blurred vision
  • Seizures (in severe cases)
  • Loss of consciousness (in severe cases)

Steps to Take When Blood Sugar is Low

  1. Check Your Blood Sugar: Verify that your blood sugar is indeed low (typically below 70 mg/dL or 3.9 mmol/L).
  2. Follow the 15-15 Rule:
    • Consume 15 grams of fast-acting carbohydrates (e.g., glucose tablets, fruit juice, regular soda, hard candies).
    • Wait 15 minutes and recheck your blood sugar.
    • If your blood sugar is still low, repeat the process.
  3. Follow Up with a Snack or Meal: Once your blood sugar is back to a safe level, eat a snack or meal containing both carbohydrates and protein to stabilize your blood sugar.
  4. Carry a Source of Fast-Acting Carbohydrates: Always carry a source of fast-acting carbohydrates with you in case of hypoglycemia.
  5. Educate Family and Friends: Make sure your family and friends know how to recognize and treat hypoglycemia.
  6. Medical Identification: Wear a medical ID bracelet or necklace indicating that you have diabetes.
  7. Contact Your Healthcare Provider: If you experience frequent or severe episodes of hypoglycemia, contact your healthcare provider.

| Condition | Cause | Symptoms | Action | |----------------|------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------| | Hyperglycemia| Overeating, missed medication dose, illness, stress, inactivity. | Frequent urination, increased thirst, blurred vision, fatigue, headache. | Check blood sugar, take medication as prescribed, drink water, exercise, adjust diet, monitor regularly, contact healthcare provider. | | Hypoglycemia| Too much medication, skipped meals, excessive exercise, alcohol. | Shakiness, sweating, dizziness, confusion, irritability, hunger, rapid heartbeat, blurred vision, seizures, loss of consciousness. | Check blood sugar, follow the 15-15 rule, follow up with a snack or meal, carry a source of fast-acting carbohydrates, educate family and friends. |

Tips for Maintaining Healthy Blood Sugar Levels

Maintaining stable blood sugar levels is a cornerstone of effective diabetes management. Consistent effort in various aspects of daily life can lead to significant improvements in overall health. Here are some helpful tips:

Related reading: Understanding Your A1C Blood Sugar Results For Better Diabetes Care

  1. Follow a Balanced Diet:
    • Focus on whole foods: Emphasize non-starchy vegetables, lean proteins, and whole grains.
    • Limit processed foods: Reduce intake of sugary drinks, refined carbohydrates, and high-fat foods.
    • Control portion sizes: Be mindful of the amount of food you're consuming at each meal.
  2. Engage in Regular Physical Activity:
    • Aim for at least 150 minutes of moderate-intensity exercise per week: This can include brisk walking, cycling, or swimming.
    • Incorporate strength training exercises: These help improve insulin sensitivity and overall muscle mass.
    • Monitor blood sugar before, during, and after exercise: This helps you understand how exercise affects your glucose levels.
  3. Take Medications as Prescribed:
    • Adhere to your medication schedule: Take your insulin or oral diabetes medications as prescribed by your healthcare provider.
    • Understand the purpose and potential side effects of each medication: This knowledge helps you manage your treatment effectively.
  4. Monitor Blood Sugar Regularly:
    • Follow your healthcare provider's recommendations for blood sugar monitoring: This may involve checking your blood sugar several times a day.
    • Keep a log of your blood sugar readings: This helps you identify patterns and trends.
  5. Manage Stress:
    • Practice relaxation techniques: Try deep breathing exercises, meditation, or yoga.
    • Engage in hobbies and activities you enjoy: These can help reduce stress and improve your overall mood.
  6. Get Enough Sleep:
    • Aim for 7-8 hours of sleep per night: Adequate sleep is essential for overall health and blood sugar control.
    • Establish a consistent sleep schedule: This helps regulate your body's natural rhythms.
  7. Limit Alcohol Consumption:
    • Drink in moderation: If you choose to drink alcohol, do so in moderation (no more than one drink per day for women and no more than two drinks per day for men).
    • Monitor blood sugar when drinking alcohol: Alcohol can affect blood sugar levels, so it's important to check your glucose levels more frequently.
    • Never drink on an empty stomach: Always eat something before or while drinking alcohol.
  8. Stay Hydrated:
    • Drink plenty of water throughout the day: Staying hydrated helps your body function properly and can help flush out excess glucose.
  9. Regular Healthcare Visits:
    • Schedule regular check-ups with your healthcare provider: These visits are essential for monitoring your overall health and making any necessary adjustments to your treatment plan.
    • Attend diabetes education classes: These classes can provide you with valuable information and support for managing your condition.

Conclusion

Understanding and managing your blood sugar levels is vital for individuals with diabetes. By regularly monitoring your blood sugar, following a balanced diet, engaging in regular physical activity, and adhering to your prescribed medication regimen, you can effectively manage your condition and prevent long-term complications. Remember to work closely with your healthcare team to develop a personalized diabetes management plan that suits your specific needs and lifestyle. With the right knowledge and proactive approach, you can live a healthy and fulfilling life with diabetes.