The Ultimate Blood Sugar Levels Chart (mg/dL & mmol/L) for Adults

23 Aug 2025

The Ultimate Blood Sugar Levels Chart (mg/dL & mmol/L) for Adults Understanding your blood sugar levels is crucial for maintaining good health, es...

The Ultimate Blood Sugar Levels Chart (mg/dL & mmol/L) for Adults

Understanding your blood sugar levels is crucial for maintaining good health, especially if you have diabetes or are at risk of developing it. This comprehensive guide provides a detailed blood sugar levels chart in both milligrams per deciliter (mg/dL) and millimoles per liter (mmol/L), along with explanations to help you interpret your results. We'll cover normal ranges, what high and low levels mean, and how they relate to different conditions like diabetes.

Why Monitor Blood Sugar Levels?

Regular blood sugar monitoring allows you and your healthcare provider to:

  • Identify patterns in your blood glucose levels.
  • Adjust your diet, exercise, and medication (if applicable) to better manage your blood sugar.
  • Detect high blood sugar (hyperglycemia) or low blood sugar (hypoglycemia) early.
  • Reduce the risk of long-term complications associated with diabetes.

Blood Sugar Levels Chart for Adults (mg/dL & mmol/L)

Here’s a detailed blood sugar chart outlining target ranges for adults, including those with and without diabetes. Remember that these are general guidelines, and your doctor may have specific targets for you based on your individual health conditions and treatment plan.

Category For People Without Diabetes (mg/dL) For People With Diabetes (mg/dL) For People Without Diabetes (mmol/L) For People With Diabetes (mmol/L)
Fasting Blood Sugar (After at least 8 hours of fasting) 70-99 mg/dL 80-130 mg/dL 3.9-5.5 mmol/L 4.4-7.2 mmol/L
2 Hours After Eating (Postprandial) Less than 140 mg/dL Less than 180 mg/dL Less than 7.8 mmol/L Less than 10.0 mmol/L
HbA1c (Average blood sugar over 2-3 months) Less than 5.7% Less than 7.0% (target may vary) N/A N/A

Understanding Your Blood Sugar Results

Normal Blood Sugar Levels

For people without diabetes, normal blood sugar levels are generally:

  • Fasting: 70-99 mg/dL (3.9-5.5 mmol/L)
  • 2 hours after eating: Less than 140 mg/dL (7.8 mmol/L)

An HbA1c of less than 5.7% also indicates normal blood sugar control over the preceding 2-3 months.

High Blood Sugar (Hyperglycemia)

Hyperglycemia, or high blood sugar, occurs when your blood glucose levels are consistently above the target range. Symptoms may include:

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

If you experience these symptoms, and your blood sugar levels are elevated according to the chart, contact your healthcare provider. Prolonged hyperglycemia can lead to serious complications such as nerve damage (neuropathy), kidney damage (nephropathy), and eye damage (retinopathy).

Low Blood Sugar (Hypoglycemia)

Related reading: Low Blood Sugar Without Diabetes A Guide To Reactive Hypoglycemia And Insulinoma

Hypoglycemia, or low blood sugar, occurs when your blood glucose levels drop below the target range. This is generally considered to be below 70 mg/dL (3.9 mmol/L). Symptoms may include:

  • Shakiness
  • Sweating
  • Confusion
  • Dizziness
  • Irritability
  • Hunger
  • Seizures (in severe cases)

If you experience these symptoms, check your blood sugar levels immediately. If your blood sugar is low, consume a quick source of glucose, such as glucose tablets, fruit juice, or hard candy. Follow up with a longer-acting carbohydrate snack. Severe hypoglycemia can be life-threatening and requires immediate medical attention.

Factors That Affect Blood Sugar Levels

Several factors can influence your blood sugar levels, including:

  • Diet: The types and amounts of carbohydrates you consume have a direct impact on your blood sugar.
  • Exercise: Physical activity can lower blood sugar by increasing insulin sensitivity and helping muscles use glucose for energy.
  • Stress: Stress hormones can raise blood sugar levels.
  • Illness: Being sick can affect blood sugar control.
  • Medications: Certain medications, such as steroids, can raise blood sugar.
  • Time of Day: Blood sugar levels can vary throughout the day, typically being lower in the morning before breakfast.

How to Check Your Blood Sugar

The most common method for checking your blood sugar is with a blood glucose meter. Here's a general overview of the process:

  1. Wash your hands thoroughly.
  2. Insert a test strip into the meter.
  3. Use a lancing device to prick your fingertip.
  4. Gently squeeze your finger to obtain a small drop of blood.
  5. Touch the test strip to the blood droplet, allowing it to be absorbed.
  6. The meter will display your blood sugar level.
  7. Record the result.

Some people also use continuous glucose monitors (CGMs), which provide continuous, real-time blood sugar readings. Consult with your doctor to determine the best method for you.

Importance of Regular Monitoring and Healthcare Provider Consultations

Related reading: Best Foods That Help Stabilize And Control Your Blood Sugar

Related reading: Continuous Glucose Monitor Cgm Vs Traditional Meter Which Is Better

This blood sugar levels chart provides valuable information for understanding and managing your blood sugar. However, it is crucial to:

  • Regularly monitor your blood sugar levels as recommended by your healthcare provider.
  • Discuss your blood sugar results and any concerns with your doctor.
  • Work with your healthcare team to develop an individualized diabetes management plan if you have diabetes.
  • Never make changes to your medication or treatment plan without consulting your doctor.

By staying informed and proactively managing your blood sugar, you can significantly improve your overall health and reduce the risk of complications. Remember that maintaining healthy blood glucose levels is a key component of a healthy lifestyle, regardless of whether you have diabetes. The information in this blood sugar levels chart is intended for educational purposes and should not be considered medical advice. Always consult with a healthcare professional for personalized guidance.