Dealing with hyperglycaemia
High blood sugar
Peer reviewed by Dr Hayley Willacy, FRCGP Last updated by St John AmbulanceLast updated 20 Nov 2016
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In this series:Type 1 diabetesInsulin
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It has not been reviewed recently and is not up to date. External links and references may no longer work.
This leaflet is created from first aid advice provided by St John Ambulance, the nation's leading first aid charity. This advice is no substitute for first aid training - find a training course near you.
In this article:
Too little insulin can cause high blood sugar (hyperglycaemia).
If it's not treated and gets worse, the person can gradually become unresponsive (going into a diabetic coma). So it's important to get them to see a doctor in case they need emergency treatment.
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What to look for
Warm, dry skin.
Rapid pulse and breathing.
Fruity sweet breath.
Really thirsty.
Drowsiness, leading to unresponsiveness if not treated.
What you need to do
Call 999 or 112 straightaway for medical help and say that you suspect hyperglycaemia.
While you wait for help to arrive, keep checking their breathing, pulse and level of response.
If they lose responsiveness at any point, open their airway, check their breathing and prepare to treat someone who's become unresponsive.
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If you're unsure whether their blood sugar is high or low
If you're not sure whether someone has high or low blood sugar, give them something sugary anyway, as this will quickly relieve low blood sugar and is unlikely to do harm in cases of high blood sugar.
If they don't improve quickly, call 999 or 112 for medical help.
If they lose responsiveness at any point, open their airway, check their breathing and prepare to treat someone who's become unresponsive.
Note: these hints are no substitute for thorough knowledge of first aid. St John Ambulance holds first aid courses throughout the country.
Adapted from the St John Ambulance leaflet: diabetic emergency. Copyright for this leaflet is with St John Ambulance.
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Article history
The information on this page is written and peer reviewed by qualified clinicians.
20 Nov 2016 | Latest version
6 Aug 2013 | Originally published
Authored by:
St John Ambulance
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