Blood sugar (glucose) is the main sugar found in your blood and your body’s primary source of energy. Type 2 diabetes affects how your body processes glucose, either by resisting the effects of insulin or not producing enough of it. Blood Sugar Is Dangerous for Type 2 Diabetes
Without a proper insulin response, blood sugar builds up in the bloodstream. This can damage organs, nerves, and blood vessels over time.
Blood Sugar Ranges: Normal, Target, and Dangerous
| Time of Day | Normal (No Diabetes) | Target for Type 2 Diabetes | Dangerously High | Dangerously Low |
| Fasting (Before Meals) | 70-99 mg/dL | 80-130 mg/dL | > 240 mg/dL | < 70 mg/dL |
| 1-2 Hours After Eating | < 140 mg/dL | < 180 mg/dL | > 300 mg/dL | < 70 mg/dL |
| Random Check | < 140 mg/dL | < 180 mg/dL | > 300 mg/dL | < 70 mg/dL |
What Is Considered High Blood Sugar? (Hyperglycemia)
Hyperglycemia occurs when blood sugar levels rise above the target range. For people with diabetes: Blood Sugar Is Dangerous for Type 2 Diabetes
180-240 mg/dL: Moderately high
240-300 mg/dL: Very high
Over 300 mg/dL: Dangerous
Over 400 mg/dL: Emergency
Signs and Symptoms of High Blood Sugar
Extreme thirst
Frequent urination
Fatigue
Blurred vision
Dry mouth
Headaches
Fruity-smelling breath
Nausea or vomiting
What Happens If High Blood Sugar Is Not Treated?
Chronic high blood sugar leads to:
Nerve damage
Kidney damage
Eye problems
Heart disease
Stroke
Extreme cases can cause:
Diabetic Ketoacidosis (DKA): More common in type 1 but possible in type 2
Hyperosmolar Hyperglycemic State (HHS): More common in type 2, extremely dangerous
When Is High Blood Sugar Considered an Emergency?
should seek emergency care if:
Your blood sugar is over 400 mg/dL
have nausea, vomiting, or fruity breath
feel confused, drowsy, or faint
are unable to bring sugar down with insulin or medication
What Is Considered Low Blood Sugar? (Hypoglycemia)
Low blood sugar is defined as:
< 70 mg/dL: Low
< 54 mg/dL: Seriously low
< 40 mg/dL: Dangerous, medical emergency
Signs and Symptoms of Low Blood Sugar
Shaking or trembling
Sweating
Rapid heart rate
Hunger
Dizziness
Anxiety or irritability
Confusion
Fainting or seizures
What Happens If Low Blood Sugar Is Not Treated?
If not treated, severe hypoglycemia can lead to:
Seizures
Loss of consciousness
Coma
Brain damage
Death
When Is Low Blood Sugar Considered an Emergency?
If you’re under 54 mg/dL and not recovering after sugar intake
experience seizures, unconsciousness, or confusion
can’t eat or drink safely
Immediate Actions: What to Do in Dangerous Situations
High Blood Sugar:
Drink water to help flush excess glucose
Avoid eating more carbs
Take prescribed insulin or oral meds
Check for ketones
Go to urgent care if symptoms worsen
For Low Blood Sugar:
Eat 15 grams of fast-acting carbs (glucose tablets, juice)
Wait 15 minutes and recheck
If still low, repeat
If unresponsive or unconscious, call 911
Causes of Dangerous Blood Sugar Fluctuations
Missed medication doses
Infections or illnesses
Overeating carbs
Skipping meals
Drinking alcohol without food
Stress
Hormonal imbalances
Intense physical activity without enough food
How to Maintain a Safe Blood Sugar Range
Monitor blood sugar multiple times a day
Eat balanced meals with carbs, fiber, and protein
Exercise regularly
Take medications on schedule
Stay hydrated
Avoid smoking and alcohol
Manage stress with mindfulness or relaxation techniques
Risk Factors That Increase Sensitivity to Dangerous Levels
Older age
Advanced diabetes
Other chronic conditions (kidney, heart disease)
History of severe hypoglycemia
Alcohol use
Mental health conditions
Conclusion
Knowing your numbers can save your life. For those living with type 2 diabetes:
Blood sugar levels above 300 mg/dL or below 54 mg/dL are dangerous
Respond quickly and appropriately to keep your levels within the safe range
Work closely with your healthcare team to create a plan
Early recognition and action are key to preventing complications. Consistent care can help you lead a healthy, active life despite diabetes.