Learn how to recognize and treat low blood sugar (hypoglycemia) and high blood sugar (hyperglycemia), when to seek emergency help, and how to prevent dangerous diabetes emergencies.
For people living with diabetes, most days involve balancing food, physical activity, medications, and blood sugar levels. However, there are times when blood sugar can become dangerously low or excessively high, leading to medical emergencies.
Knowing how to recognize the warning signs and respond quickly can prevent serious complications and even save lives.
This guide explains:
- What low and high blood sugar mean
- Common symptoms
- Emergency treatment steps
- When to seek immediate medical care
- How to prevent future episodes
Every person with diabetes—and their family members, friends, teachers, and caregivers—should know these essential facts.
Table of Contents
- Understanding Blood Sugar Emergencies
- What Is Low Blood Sugar?
- What Is High Blood Sugar?
- Symptoms of Low Blood Sugar
- Symptoms of High Blood Sugar
- Severe Hypoglycemia
- Diabetic Ketoacidosis (DKA)
- Hyperosmolar Hyperglycemic State (HHS)
- First Aid for Low Blood Sugar
- First Aid for High Blood Sugar
- Emergency Warning Signs
- Preventing Blood Sugar Emergencies
- Creating an Emergency Plan
- Frequently Asked Questions
- Final Thoughts
Understanding Blood Sugar Emergencies
Blood sugar levels naturally rise and fall throughout the day.
However, when blood sugar becomes:
- Too low, or
- Too high,
the body may not function properly.
Some blood sugar emergencies develop gradually, while others can happen very quickly.
Knowing what to do can make a major difference.
What Is Low Blood Sugar?
Low blood sugar is called:
Hypoglycemia
It generally refers to blood sugar levels below:
70 mg/dL
However, symptoms may occur at different levels in different people.
Why Is Low Blood Sugar Dangerous?
The brain relies heavily on glucose for energy.
When blood sugar falls too low:
- Thinking becomes impaired.
- Coordination decreases.
- Loss of consciousness may occur.
Severe hypoglycemia is a medical emergency.
What Causes Low Blood Sugar?
Common causes include:
- Taking too much insulin
- Taking certain diabetes medications
- Skipping meals
- Eating less than usual
- Delayed meals
- Excessive exercise
- Drinking alcohol without eating
Who Is Most at Risk?
The risk is higher for people who:
- Use insulin
- Take certain diabetes medications
- Have had previous episodes of hypoglycemia
- Have kidney disease
- Have irregular eating patterns
Symptoms of Low Blood Sugar
Symptoms often develop quickly.
Early Symptoms
- Hunger
- Sweating
- Shaking
- Nervousness
- Fast heartbeat
- Dizziness
- Weakness
- Tingling around the mouth
Moderate Symptoms
- Confusion
- Blurred vision
- Difficulty concentrating
- Irritability
- Headache
- Difficulty speaking
Severe Symptoms
- Inability to swallow
- Loss of coordination
- Seizures
- Loss of consciousness
This is a medical emergency.
What Is High Blood Sugar?
High blood sugar is called:
Hyperglycemia
It occurs when blood sugar rises above the target range.
Many people consider blood sugar consistently above:
180 mg/dL after meals
or significantly elevated fasting levels to be concerning.
Your individual target may vary.
What Causes High Blood Sugar?
Common causes include:
- Missing medications
- Illness
- Stress
- Eating more carbohydrates than usual
- Physical inactivity
- Hormonal changes
- Infection
Symptoms of High Blood Sugar
High blood sugar often develops gradually.
Early Symptoms
- Increased thirst
- Frequent urination
- Dry mouth
- Fatigue
- Blurred vision
- Headache
More Serious Symptoms
- Extreme thirst
- Nausea
- Vomiting
- Weight loss
- Weakness
- Dehydration
Severe Symptoms
- Confusion
- Difficulty breathing
- Severe dehydration
- Loss of consciousness
These symptoms require urgent medical attention.
What Is Diabetic Ketoacidosis (DKA)?
DKA is a serious complication that occurs when the body does not have enough insulin.
Without insulin:
- Glucose cannot enter the cells.
- The body starts burning fat for energy.
- Acids called ketones build up in the blood.
DKA is most common in:
- Type 1 diabetes
- Newly diagnosed diabetes
However, it can also occur in Type 2 diabetes.
Symptoms of DKA
- Nausea
- Vomiting
- Abdominal pain
- Fruity-smelling breath
- Rapid breathing
- Severe weakness
- Confusion
DKA requires emergency medical treatment.
What Is Hyperosmolar Hyperglycemic State (HHS)?
HHS is another serious diabetes emergency that usually occurs in Type 2 diabetes.
Blood sugar becomes extremely high, causing severe dehydration.
Symptoms of HHS
- Extreme thirst
- Dry skin
- Weakness
- Confusion
- Drowsiness
- Loss of consciousness
HHS is a medical emergency.
First Aid for Low Blood Sugar
If the person is awake and able to swallow:
Step 1
Consume approximately:
15 grams of fast-acting carbohydrate.
Examples include:
- Glucose tablets
- Fruit juice
- Sugar dissolved in water
- Regular soft drink
- Hard candy
Step 2
Wait:
15 minutes.
Step 3
Check blood sugar again if possible.
If blood sugar remains low or symptoms persist, repeat treatment.
Step 4
Once blood sugar improves, eat a small snack or meal if the next meal is not soon.
What Should You Avoid?
Avoid foods that contain large amounts of fat, such as:
- Chocolate
- Ice cream
These may raise blood sugar more slowly.
Severe Hypoglycemia: When the Person Is Unconscious
If the person:
- Cannot swallow
- Is having a seizure
- Is unconscious
Do NOT give food or drink.
Doing so may cause choking.
Call emergency medical services immediately.
First Aid for High Blood Sugar
If blood sugar is elevated:
Stay Hydrated
Drink water unless your healthcare provider has advised otherwise.
Monitor Symptoms
Watch for:
- Vomiting
- Difficulty breathing
- Increasing weakness
Take Medications as Directed
Follow your diabetes treatment plan.
Rest and Monitor
Continue monitoring blood sugar if possible.
When Should You Seek Emergency Help for High Blood Sugar?
Seek immediate medical attention if:
- Vomiting persists
- Breathing becomes difficult
- The person becomes confused
- Fruity-smelling breath develops
- Severe dehydration occurs
- Loss of consciousness occurs
Emergency Warning Signs: Call for Help Immediately
Low Blood Sugar Emergency
- Seizure
- Unconsciousness
- Inability to swallow
High Blood Sugar Emergency
- Confusion
- Difficulty breathing
- Severe weakness
- Persistent vomiting
- Severe dehydration
- Loss of consciousness
Blood Sugar Emergencies in Children
Children may not recognize symptoms.
Parents and caregivers should watch for:
- Irritability
- Sleepiness
- Sweating
- Pale skin
- Confusion
- Changes in behavior
Children with diabetes should have an emergency plan at school and at home.
Blood Sugar Emergencies in Older Adults
Older adults may have:
- Fewer symptoms
- Atypical symptoms
- Delayed recognition
Caregivers should pay close attention to:
- Confusion
- Dizziness
- Sudden weakness
- Changes in behavior
Can Stress Cause Blood Sugar Emergencies?
Stress can increase blood sugar levels and make diabetes management more challenging.
Learning healthy stress-management techniques can help.
Can Exercise Cause Low Blood Sugar?
Yes.
Physical activity can lower blood sugar, especially in people using insulin or certain medications.
Planning ahead and monitoring blood sugar can reduce risk.
Preventing Low Blood Sugar
Helpful strategies include:
✓ Eat meals regularly.
✓ Do not skip meals.
✓ Understand your medications.
✓ Monitor blood sugar.
✓ Carry a fast-acting carbohydrate source.
✓ Plan for exercise.
Preventing High Blood Sugar
Helpful strategies include:
✓ Take medications as prescribed.
✓ Stay active.
✓ Drink enough water.
✓ Monitor blood sugar regularly.
✓ Follow your meal plan.
✓ Seek medical advice during illness.
Create a Diabetes Emergency Kit
Consider keeping:
✓ Glucose tablets
✓ Blood sugar monitor
✓ Medications
✓ Emergency contact numbers
✓ Medical information card
✓ Snacks
✓ Water
Wear Medical Identification
A medical identification bracelet or card can help emergency responders quickly understand your condition.
Questions to Ask Your Healthcare Provider
- What should my target blood sugar range be?
- What should I do if my blood sugar becomes too low?
- When should I seek emergency care?
- How should I manage diabetes during illness?
- What emergency supplies should I keep?
Frequently Asked Questions
Is low blood sugar always dangerous?
Mild low blood sugar can often be treated quickly, but severe hypoglycemia is a medical emergency.
Can high blood sugar become an emergency?
Yes.
Very high blood sugar can lead to serious complications such as DKA or HHS.
Can people without diabetes have low blood sugar?
Yes, although it is less common.
Is one high blood sugar reading an emergency?
Not necessarily.
Patterns and symptoms are important.
Should I keep sugar with me at all times?
Many people who use insulin or certain medications benefit from carrying a fast-acting carbohydrate source.
A Diabetes Emergency Checklist
✓ Know the symptoms of low blood sugar.
✓ Know the symptoms of high blood sugar.
✓ Keep emergency contacts available.
✓ Carry fast-acting carbohydrates.
✓ Wear medical identification.
✓ Teach family members and friends what to do.
✓ Follow your treatment plan.
Preparation can save lives.
Final Thoughts
Low and high blood sugar emergencies can be frightening, but they are often manageable when recognized early.
Understanding the symptoms, knowing basic first aid, and having an emergency plan can help prevent serious complications and provide peace of mind.
Whether you live with diabetes or care for someone who does, learning these skills is one of the most important steps you can take.
Knowledge, preparation, and quick action can make all the difference in a blood sugar emergency.
Related Articles in the Diabetes Knowledge Hub
- What Is Diabetes? A Complete Beginner’s Guide
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- Understanding HbA1c and Blood Sugar Numbers
- Best Indian Diet Plan for Diabetes
- Exercise Plan for People with Diabetes
- Diabetes and Heart Disease
- Diabetes and Kidney Health
- Diabetes in Children: A Parent’s Guide
- 50 Common Myths About Diabetes Debunked