What is hypoglycaemia?
Causes
Symptoms
What to do if you feel symptoms
How is it treated?
What is Impaired Awareness of Hypoglycaemia?
What is hypoglycaemia?
Hypoglycaemia or low blood glucose level (BGL) is a condition which occurs when the BGL falls below 4 mmol/L.
Hypoglycaemia is not a problem for those who manage their diabetes with healthy eating and exercise alone. Hypoglycaemia is most common in people using insulin and certain diabetes medication.
Diabetes medications that can cause hypoglycaemia are known as sulphonylureas.
These include:
| Chemical name | Brand name |
| Gliclazide | Diamicron, Glyade,Diamicron MR,Nidem |
| Glibenclamide | Daonil, Semi Daonil,Glimel |
| Glibenclamide/Metformin |
Glucovance |
| Glipizide | Melizide, Minidiab |
| Glimepiride | Amaryl, Dimirel |
Please note that other diabetes medications (please refer to medication for type 2 diabetes) on their own do not generally cause hypoglycaemia, however hypoglycaemia may occur when used in conjunction with sulphonylureas.
What are the main causes of hypoglycaemia?
Hypoglycaemia can be caused by one or a number of events such as
- Delaying or missing a meal
- Not eating enough carbohydrate
- Drinking alcohol
- Too much insulin or diabetes medication
- Vomiting
- More strenuous exercise than usual
- Unplanned physical activity
Note: Hypoglycaemia may be delayed for up to 12 hours after exercise
What are the symptoms of hypoglycaemia?
Symptoms of hypoglycaemia can vary between individuals. It important to get to know your body and become aware of the messages your body is sending you.
Common symptoms are
- Weakness, trembling or shaking
- Feeling dizzy/ light headed, headache
- Sweating
- Hunger
- Behaviour changes such as aggression /irritability, tearful/ crying
- Lack of concentration
- Tingling around the lips
- Racing heart beat
What should be done if you feel symptoms of hypoglycaemia?
Check your BGL, if you are able to. If you are unable to do so, treat as a hypo just to be sure.
How is hypoglycaemia treated?
Step 1 (most important)
- Have some quick acting easily absorbed carbohydrate. For example, glucose tablets equivalent to 15 grams carbohydrate (Read the label on packing to ensure you are getting the correct dose) or
- Six to seven jelly beans or
- Half a can regular soft drink (not diet/ sugar free) or
- Three teaspoons sugar or honey or
- Half a glass fruit juice
Note: If you are taking Glucobay (Acarbose), hypoglycaemia must be treated with glucose.
If possible re-test BGL after 10 to15 minutes to ensure it has risen above 4mmol/L. If symptoms persist or BGL remains below 4mmol/L, repeat Step 1.
Step 2
If your next meal is more than 20 minutes away, you will need to eat some longer acting carbohydrate for eg,
- One slice of bread or
- One glass of milk or
- One piece of fruit or
- Two to three pieces of dried apricots, figs or other dried fruit or
- One tub natural low fat yoghurt or
- Six small dry biscuits and cheese
What happens if hypoglycaemia is not treated?
If not treated promptly your BGL can continue to drop which may lead to:
- Loss of coordination
- Confusion
- Slurred speech
- Loss of consciousness/ fitting
What should be done if the person with diabetes is unconscious, drowsy or unable to swallow?
- This is a diabetic emergency and assistance and treatment must be provided
- Never give food or drink by mouth
- Place person on their side make sure airway is clear
- Give an injection of glucagon if available and you are trained to give it
- Phone for an ambulance (Dial 000) let the operator know that it is a diabetic emergency
- Wait with the person until help arrives
- When they regain consciousness, the person will require carbohydrate to maintain their BGL
Glucagon
Glucagon is a hormone which raises the blood glucose level. It is injected in a similar way to insulin and is used to reverse severe hypoglycaemia in the person with diabetes (If the person cannot swallow, is unconscious or fitting).
Glucagon stimulates the release of glucose from the liver and usually raises the blood glucose level 10 minutes after injecting and lasts for approximately half an hour.
People with diabetes using insulin or blood glucose lowering medications should discuss glucagon use with their doctor.
Glucagon needs to be administered by someone other than the person with diabetes which means family members and or friends should be trained in how to use it.
Glucagon is only available on prescription from your doctor.
People with diabetes using insulin or blood glucose lowering medications should discuss glucagon use with their doctor.
What is Impaired Awareness of Hypoglycaemia?
Impaired awareness of hypoglycaemia (IAH) occurs when people do not feel the early warning symptoms of hypoglycaemia occurring or only experience symptoms when their blood glucose levels drop very low. This usually occurs in those who hypo frequently or have had diabetes for many years.
You may have impaired awareness of hypoglycaemia if
- Your BGL is less than 4mmol/L before meals or on waking
- Your BGL is less than 3.5 mmol/L and you still feel okay
- You have had a recent history of severe hypoglycaemia (seizure or loss of concentration) without warning signs.
- You have noticed that lower blood glucose levels are required before symptoms of hypoglycaemia are felt.
If you think you could have impaired awareness of hypoglycaemia it is important you discuss this with your doctor or diabetes educator as soon as possible. Blood glucose targets need to be raised for several weeks for symptoms of hypo to be regained.
People with type 2 diabetes can also have impaired awareness of hypoglycaemia but it is less common and occurs generally in people who are on insulin and/ or who have had diabetes for a long time.
What else should I know about?
- Always carry hypo treatment with you if you are taking insulin or medications that lower your blood glucose level
- Wear identification that says you have diabetes
- If you are participating in physical activity/ sport, monitor your blood glucose level before commencing activity and during to ensure it remains stable. You may also need to eat extra carbohydrate to maintain a safe blood glucose level
- If you are driving and develop signs of hypo, pull over to side of road and treat the hypo. Wait at least 30 minutes after your blood glucose reads above 5 mmol/L and you feel better before you resume driving.
- You should always check your blood glucose level before driving and REMEMBER your blood glucose level must be above 5 to drive.
- If you have an episode of severe hypoglycaemia involving loss of consciousness you should not resume driving until you have medical clearance to do so. Download the Driving and Diabetes booklet for further information
- Make sure that your family, friends, school staff, co-workers and carers know how to treat and recognise hypoglycaemia
- If taking Acarbose (Glucobay) carry pure glucose with you such as glucose tablets, glucose gel or Lucozade
- Make sure you eat carbohydrates if drinking alcohol






















