Hypoglycaemia (low blood glucose)

A hypo, or hypoglycaemia, is when the glucose in your blood drops too low. In Australia a reading below 4.0 mmol/L counts as a hypo for most people living with diabetes.^1,2 It happens when the things that lower glucose, such as insulin or some glucose lowering tablets, outweigh the things that raise it. Common triggers are a late or missed meal, less carbohydrate than usual, unplanned or harder activity, alcohol, vomiting or diarrhoea, and breastfeeding.^1,2 Sometimes there is no clear reason at all, which is frustrating but worth recording anyway.²

Australian guidance uses a set sequence. Take about 15 g of quick acting carbohydrate, for example 4 glucose tablets, 6 or 7 regular jellybeans, half a can (150 mL) of regular soft drink, half a glass (125 mL) of fruit juice, or three teaspoons of sugar or honey.^1,2 Wait 10 to 15 minutes, then check again. If you are still below 4.0 mmol/L, repeat that step.¹ Once you are above 4.0 mmol/L, eat longer acting carbohydrate such as a slice of bread, a piece of fruit or 250 mL of milk, unless your next meal is within 15 to 20 minutes.^1,2 Your own plan sets the amounts.¹

A severe hypo is one you cannot treat yourself, where you need someone else to help.¹ Some people stop getting early warning signs at all, which is called impaired awareness of hypoglycaemia. It becomes more likely the longer you have lived with diabetes and after repeated lows, and it substantially raises the risk of a severe hypo.^1,4 It can improve over weeks to months if further lows are avoided.⁴ That is worth working on, because it changes your safety at home, at work and behind the wheel, where the national driver standard sets its own rules.^3,4