Hypoglycaemia (Low Blood Sugar)

Last Updated: July 3, 2026

Key Points

Blood sugar below 4mmol/L is considered low
Requires quick treatment to prevent worsening
Most common in people with diabetes
Often treatable at home with sugary foods

Overview

Hypoglycaemia, commonly known as low blood sugar, happens when the glucose (sugar) level in your blood drops below 4mmol/L. Glucose is your body's main source of energy, so when levels are too low, it can cause various symptoms and, if severe, become dangerous. It's crucial to treat low blood sugar quickly. This condition mainly affects people with diabetes, particularly those who use insulin or certain other diabetes medications. These treatments aim to lower blood sugar, but sometimes they can lower it too much. It is rare for people without diabetes to experience true hypoglycaemia. Management typically involves consuming fast-acting sugars to raise blood glucose levels, followed by longer-acting carbohydrates. Understanding the symptoms and knowing how to respond is vital for those at risk.

Signs and Symptoms

Feeling hungry
Feeling dizzy
Feeling anxious or irritable
Sweating
Shaking or trembling
Tingling lips
Heart palpitations (fast heartbeat)
Feeling tired or weak
Blurred vision
Feeling confused
Severe: seizure or unconsciousness

Things That Increase the Risk

Taking too much insulin or certain diabetes medications
Incorrect insulin injection technique
Missing or delaying meals
Not eating enough carbohydrates
Intense exercise without adjusting food or medication
Drinking alcohol, especially without eating
Malnutrition (rarely, in non-diabetics)
Addison's disease (rarely, in non-diabetics)
Pancreatic tumour (rarely, in non-diabetics)

Diagnosis

Checking blood sugar levels with a meter
Recognizing typical symptoms
Review of medical history and medications

Treatment & Management

Consume quick-acting sugary food or drink (e.g., fruit juice, glucose tablets)
Recheck blood sugar after 10-15 minutes
Repeat sugary snack if blood sugar remains low
Eat a longer-acting carbohydrate once blood sugar stabilizes
For severe cases: administer glucagon injection (if available)
Call emergency services if unconscious or not recovering

Prevention

Follow your diabetes treatment plan diligently
Check blood sugar levels regularly
Always carry quick-acting sugary snacks or drinks
Carry a glucagon injection kit and medical ID
Educate family and friends on how to treat severe low blood sugar
Consider using a continuous glucose monitor
Do not skip or delay meals
Limit alcohol intake and avoid drinking without eating

Available Treatments

Explore our range of treatment options for Hypoglycaemia (Low Blood Sugar):