Fiducia TogetherDiabetic ketoacidosis
Also called DKA
A life-threatening emergency in type 1 diabetes, and how many children are first diagnosed. Ketones, not glucose, are what to measure.
Important: This page is general information, not medical advice, and it is not a diagnosis. If you are worried about your health or someone else's, speak to a GP, pharmacist, or call 111. In an emergency, call 999.
What it is
A dangerous complication in which a lack of insulin forces the body to break down fat for fuel, producing acidic ketones that poison the blood.
It happens mainly in type 1 diabetes, triggered by illness, infection, missed insulin, pump failure, or as the first presentation of undiagnosed diabetes. A significant proportion of children are diagnosed with type 1 diabetes only when they arrive in DKA, which is why the four Ts campaign exists: toilet, thirsty, tired, thinner.
It can also occur in type 2 diabetes, and importantly it can occur with a **normal or only mildly raised glucose** in people taking SGLT2 inhibitor drugs, the gliflozins. That euglycaemic DKA is regularly missed because everybody looks at the glucose. Anybody on those drugs who is unwell, vomiting or not eating should have ketones checked regardless of the glucose reading.
The key measurement is ketones, not glucose. Anybody with type 1 diabetes should have a ketone meter and know the thresholds.
Sick day rules are the prevention: **never stop insulin**, even when not eating. Stopping insulin because somebody is not eating is one of the commonest causes of DKA and one of the most preventable.
Signs you might notice
Very thirsty, passing large amounts of urine.
Nausea and vomiting, abdominal pain.
Deep, sighing, rapid breathing.
Breath smelling sweet, like pear drops or nail varnish remover.
Drowsiness, confusion, and eventually unconsciousness.
Blood ketones above 3.0 mmol/L, or urine ketones at ++ or more.
999 immediately for vomiting, drowsiness, confusion, deep rapid breathing, or ketones above 3.0.
In an undiagnosed child, the four Ts: going to the **toilet** a lot, being unusually **thirsty**, feeling **tired**, and getting **thinner**. A same-day finger-prick glucose test is all that is needed to check.
How it can affect day-to-day life
The prevention is entirely about the sick day rules, and they need to be written down before anybody is ill, not looked up at 3am.
The core rules: never stop insulin; check glucose and ketones more often, at least four-hourly; keep drinking; take extra rapid-acting insulin according to the agreed plan when ketones are raised; and get help early.
Pump users are at higher risk because there is no long-acting insulin as a backstop; a blocked cannula can cause DKA within hours. Every pump user needs a backup pen and a plan.
In care settings and schools, the crucial instruction is that food refusal is not a reason to withhold insulin, and staff need that written explicitly.
For anyone on an SGLT2 inhibitor, the drug should usually be stopped during acute illness, before surgery, and when fasting. That is a frequently missed instruction.
DKA is frightening and often followed by real anxiety about recurrence; support for that is legitimate.
Supporting someone well
Get the sick day rules written down and kept where they can be found in the middle of the night.
Never stop insulin, even if not eating.
Have a ketone meter and in-date strips, and know the thresholds.
Check ketones whenever unwell, whenever glucose is persistently high, and whenever there is vomiting, regardless of the glucose reading in anybody on a gliflozin.
Keep drinking sugar-free fluids, and take extra rapid-acting insulin as per the plan.
Call 999 for vomiting, drowsiness or deep rapid breathing. Vomiting with ketones is not something to manage at home.
For pump users, keep a backup insulin pen and know how to switch to injections.
Teach the four Ts to anyone who looks after children.
Stop SGLT2 inhibitors during acute illness or fasting, as advised.
Where to get help
999 for vomiting, drowsiness, confusion or deep rapid breathing.
The diabetes team's contact number for advice while unwell; use it early rather than late.
A GP practice the same day for a child with the four Ts.
Diabetes UK helpline: 0345 123 2399, and their sick day rules guidance.
Tools we make that might help
These are our own products. We have put them here because they do something specific for this condition, not because every page needs a list.
Fiducia Guardian
Sick day rules and ketone readings held with the care record, so nobody has to work out at 3am whether to give insulin.
Last reviewed 2026-08-28 by Fiducia Together · Next review due 2027-08-28
Important: This page is general information, not medical advice, and it is not a diagnosis. If you are worried about your health or someone else's, speak to a GP, pharmacist, or call 111. In an emergency, call 999.