HealthInfo Canterbury
Low blood glucose (hypoglycaemia)
Huka ā-toto hakahaka
Hypoglycaemia, also called a hypo, means you have a low blood glucose (sugar) level. Any blood glucose level less than 4 is low.
It happens mainly if you inject insulin, but it can also happen with some tablets.
Important
A hypo can happen quickly, and you need to treat it immediately. If you do not treat your hypo, you can become unconscious.
Test your blood glucose level then follow the self-care advice below.
Tell your whānau (family) and friends how to treat a hypo so they can help you if you cannot help yourself. If you're unconscious, they should:
- immediately phone 111 for an ambulance, then
- give you an injection of glucagon.
Symptoms of a hypo
You can get hypoglycaemia if you have not eaten for a long time, have given yourself too much insulin or exercised hard without having any extra food.
If you're having a hypo, you're likely to have some or all of the following symptoms:
- pins and needles in your mouth and tongue
- sweating
- pale skin
- shaking hands or legs
- a headache
- blurred vision
- a fluttering heart (palpitations).
You may also feel:
- dizzy
- nervous
- sleepy
- hungry
- confused
- unable to concentrate.
You might have symptoms of a hypo when your blood glucose level is not below 4 if:
- your blood glucose level is regularly high, and it quickly drops to normal
- you're anxious.
Reducing your risk of a hypo
You can reduce your risk of having a hypo if you avoid the things that can cause hypos. These include:
- missing or delaying a meal
- not having enough starchy food (carbohydrates) with your meal or snack
- being more physically active than usual and not having extra food to fuel it
- having too much insulin or taking too many diabetes tablets
- drinking too much alcohol or drinking alcohol on an empty stomach
- allowing too much time between your injection and your meal
- changing the time when you have your insulin or tablets.
You should always carry a hypo treatment with you. If you do not treat a hypo, you may lose consciousness or have a fit or seizure. This is rare and usually only if you have Type 1 diabetes, but it's important to treat all episodes of hypoglycaemia correctly.
Self-care for a hypo
If you think there is a danger you might be having a hypo, even without symptoms, test your blood glucose level.
If your blood glucose is less than 4, have one of the following options:
- three or four glucose tablets
- one tablespoon of glucose powder dissolved in water
- four to six large jelly beans
- one small glass (150 ml) of fruit juice
- one small glass (150 ml) of "ordinary" (non‑diet) soft drink
- one tablespoon of jam or sugar
- two sachets of Hypo-Fit gel (available from Diabetes Christchurch and some pharmacies).
Wait 15 minutes then test your blood glucose again. If your blood glucose is still below 4, have a repeat helping from the above list.
Once your blood glucose is above 4, have:
- a meal if it's due, or
- insulin just before or straight after your meal if it's due, or
- a snack such as:
- a sandwich made with one piece of bread, or
- a piece of fruit such as half a banana, or
- a glass of milk.
Do not drive when you're having a hypo as you risk having an accident or losing your licence.
Tell your general practice team or diabetes nurse if you keep having hypos.
On the next page: Guidelines for giving glucagon
Written by Christchurch Diabetes Centre. Adapted by HealthInfo clinical advisers. Last reviewed November 2022.
SourcesReview key: HIDIA-21832
