The Rule of 15
The one treatment to be able to do without thinking: 15g of fast sugar, a full 15 minutes of waiting, then a re-check that decides what happens next.
What to know
What the two 15s mean
Give 15g of fast-acting carbohydrate, then wait a full 15 minutes before testing again. Treating and then re-treating too early is the most common mistake, it pushes glucose from low to very high.
15g, the everyday version
6 to 7 jelly beans, half a can of regular (not diet) soft drink, a small 150ml juice, 3 teaspoons of sugar stirred into water, or 3 to 4 glucose tablets. Any one of these does the job.
What not to reach for first
Chocolate, cake, milk and milky drinks act slowly because fat and protein hold up absorption. They have a place afterwards, never as the first treatment.
The number decides, not the feeling
Someone can look and sound better and still sit under 4.0 mmol/L. The test at 15 minutes is what tells you whether to repeat the 15g.
Finish with a slower carb
Once they are above 4.0 and their next meal is more than 20 minutes away, give something longer-acting, like a sandwich, a piece of fruit or a glass of milk, so the low does not come straight back.
When nothing goes in the mouth
If they are unconscious, fitting, or cannot swallow safely, no food or drink, ever. Roll them onto their side, call 000, and give glucagon if it is on hand and you have been shown how.
What to do, in order
- Check the glucose if you can. Below 4.0 mmol/L, treat it as a hypo.
- Give 15g of fast-acting carbohydrate straight away.
- Stay with them and wait a full 15 minutes, don't keep topping up in that time.
- Re-check the glucose. Still below 4.0? Give another 15g and wait another 15 minutes.
- Above 4.0? Give a longer-acting carb if their next meal is more than 20 minutes away.
- Drowsy, confused, unable to swallow, or fitting at any point: nothing by mouth, roll them onto their side and call 000.
Test your instincts
Read each situation, then reveal the options.
Your colleague feels shaky and sweaty and their meter reads 3.6 mmol/L. They ask you for something to eat.
What do you give them first?
Show the optionsHide the options
You gave 15g of glucose tablets at 10:00. At 10:05 they say they feel fine and ask for more.
What's the best response?
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Fifteen minutes on, their re-test reads 3.7 mmol/L. They are awake, talking, and swallowing normally.
What now?
Show the optionsHide the options
This is general first aid education, not personal medical advice. In an emergency in Australia, call 000.