Hypoglycaemia (low blood sugar)
2-minute read
Hypoglycaemia, or a ‘hypo’, is having too little glucose (sugar) in your blood (below 4 mmol/L).
If you or anyone you are with develops signs of hypoglycaemia, ring triple zero (000) and ask for an ambulance. If the person can’t swallow, don’t try to give them anything to eat or drink.
A hypo can happen for many reasons such as:
- you have delayed or missed a meal or snack
- you have exercised more than usual (it can happen up to 12 hours after you have exercised)
- you haven't eaten enough carbohydrate
- you have drunk too much alcohol
- you have taken too much insulin
If you have a hypo, you might:
- feel hungry
- feel sweaty
- feel weak
- look pale
- feel dizzy or light-headed
- have a headache
- have tingling lips
- be trembling or shaking
- experience mood change
People with a more severe hypo can:
- be confused
- find it hard to concentrate
- feel irritable or nervous
- have slurred speech
- behave irrationally or strangely, which can sometimes be mistaken for drunkenness
- have a seizure
People with hypos who don’t get treatment can become unconscious. It can be fatal.
If the hypo is mild, and the person affected is behaving rationally, here are some things you can do. If your blood glucose level (BGL) is below 4 mmol/L:
Step 1
Have 15 grams of fast-acting carbohydrate, such as:
- 6-7 jellybeans OR
- half a can of regular soft drink (not ‘diet’) OR
- half a glass of fruit juice OR
- 3 teaspoons of sugar or honey OR glucose tablets equivalent to 15 grams carbohydrate
Step 2
Wait 15 minutes, re-check your blood glucose levels to see if your BGL has risen above 4 mmol/L.
- If your BGL has risen above 4 mmol/L go to Step 3.
- If your BGL is still below 4 mmol/L, repeat Step 1.
Step 3
Eat a snack or meal with a longer-acting carbohydrate, such as:
- a slice of bread OR
- 1 glass of milk OR
- 1 piece of fruit OR
- 2-3 pieces of dried apricot, figs or other dried fruit OR
- 1 tub of natural low-fat yoghurt OR
- pasta OR
- rice
If your blood sugar level remains low, immediately contact your diabetes nurse or educator, or your doctor, for advice.
If you have had hypoglycaemia, monitor your blood sugar level regularly to check it is remaining under control.
Learn more here about the development and quality assurance of healthdirect content.
Last reviewed: July 2020