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HealthInfo Waitaha 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.


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:

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:

hypo signs

You may also feel:

You might have symptoms of a hypo when your blood glucose level is not below 4 if:

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:

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.

jellybeansIf your blood glucose is less than 4, have one of the following options:

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:

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.


Page reference: 178645

Review key: HIDIA-21832