What blood sugar level indicates diabetes?

A fasting blood sugar of 126 mg/dL or higher on two separate tests, or an HbA1c of 6.5% or above, is used to diagnose diabetes.

What is considered low blood sugar?

Blood sugar below 70 mg/dL is classified as hypoglycemia. Levels below 54 mg/dL are considered clinically significant and require immediate treatment.

What should blood sugar be 2 hours after eating?

For non-diabetic individuals, blood sugar should be under 140 mg/dL two hours after a meal. For people with diabetes, the ADA recommends staying under 180 mg/dL.

How often should I check my blood sugar?

People with type 1 diabetes typically test 4–10 times daily. Those with type 2 diabetes on insulin may test 2–4 times daily. Your doctor will recommend a schedule based on your treatment plan.

What is the difference between blood glucose and HbA1c?

Blood glucose measures your sugar level at a single moment in time, while HbA1c reflects your average blood sugar over the past 2–3 months, giving a broader picture of long-term control.

Can stress raise blood sugar levels?

Yes. Physical and emotional stress triggers cortisol and adrenaline release, which raise blood glucose. This is important to consider when interpreting unexpectedly high readings.

Which glucose meter is best for home monitoring?

Look for a meter with high clinical accuracy (ISO 15197:2013 certified), small blood sample size, memory storage, and affordable test strips. MDS Diabetes offers a range of reliable options at mdsdiabetes.com.

Blood Sugar Levels Chart: Normal, Low & High

Quick specs

Normal Fasting Range	70–99 mg/dL
Diabetes Fasting Threshold	126+ mg/dL
Normal Post-Meal (2hr)	Under 140 mg/dL
Hypoglycemia Threshold	Below 70 mg/dL
Normal HbA1c	Below 5.7%
Diabetes HbA1c Threshold	6.5%+

Key Takeaways

Normal fasting blood sugar is 70–99 mg/dL (3.9–5.5 mmol/L)
Readings above 126 mg/dL fasting on two occasions indicate diabetes
Hypoglycemia is defined as blood sugar below 70 mg/dL
HbA1c below 5.7% is considered normal; 6.5%+ confirms diabetes
Regular home monitoring with a reliable glucose meter is essential

Blood Sugar Levels Chart

Category	Fasting (mg/dL)	2hr Post-Meal (mg/dL)	HbA1c (%)
Normal	70–99	Under 140	Below 5.7
Prediabetes	100–125	140–199	5.7–6.4
Diabetes	126+	200+	6.5+
Hypoglycemia	Below 70	Below 70	N/A

Understanding Normal Blood Sugar Ranges

Blood glucose levels fluctuate naturally throughout the day. A fasting reading taken after 8+ hours without food between 70–99 mg/dL is considered normal for non-diabetic adults. After meals, levels rise temporarily; readings under 140 mg/dL two hours post-meal are healthy.

Target Ranges for People with Diabetes

Before meals: 80–130 mg/dL (ADA guideline)
2 hours after meals: Under 180 mg/dL
Bedtime: 100–140 mg/dL
HbA1c target: Below 7.0% for most adults

Low Blood Sugar (Hypoglycemia)

Hypoglycemia occurs when blood glucose drops below 70 mg/dL. Symptoms include shakiness, sweating, confusion, and rapid heartbeat. Severe hypoglycemia (below 54 mg/dL) requires immediate treatment. The standard response is the 15-15 rule: consume 15g fast-acting carbohydrates, wait 15 minutes, retest.

High Blood Sugar (Hyperglycemia)

Persistent readings above 180 mg/dL after meals or above 130 mg/dL fasting indicate hyperglycemia. Long-term high blood sugar damages kidneys, nerves, and blood vessels. Symptoms include frequent urination, excessive thirst, and fatigue. Diabetic ketoacidosis (DKA) is a dangerous complication requiring emergency care.

How to Monitor Blood Sugar at Home

A reliable blood glucose meter is the cornerstone of diabetes management. MDS Diabetes offers clinically accurate glucose meters that deliver fast results with minimal blood sample size. Look for meters with memory storage, app connectivity, and low-cost test strips for long-term affordability.

When to Test

Fasting: first thing in the morning
Before and 2 hours after each meal
Before and after exercise
At bedtime
Whenever symptoms of low or high blood sugar appear

Factors That Affect Blood Sugar

Diet: Carbohydrate quality and quantity have the greatest impact
Exercise: Physical activity generally lowers blood glucose
Stress: Cortisol raises blood sugar levels
Illness: Infections can cause significant spikes
Medication: Insulin and oral medications directly regulate glucose

References & Sources

Worth it if you…

✓Clear reference ranges for all health statuses

✓Covers fasting, post-meal, and HbA1c in one chart

✓Actionable monitoring schedule included

Watch out if you…

△Individual targets may vary — always consult your doctor

△mmol/L conversions require a separate calculation

Frequently asked questions

A normal fasting blood sugar level is between 70–99 mg/dL (3.9–5.5 mmol/L) for non-diabetic adults, measured after at least 8 hours without food.

Editorial note

This article is for educational purposes only and does not constitute medical advice. Always consult your healthcare provider before making changes to your diabetes management. Last reviewed: July 5, 2026 by the MDS Diabetes editorial team.

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Blood sugar levels chart: normal, low, and high ranges