Short Term Complications
Low Glucose
Hypoglycaemia, more commonly known as a hypo, is when your blood glucose levels go low, typically below 4mmol/L.
Everyone’s symptoms are slightly different, but the most common symptoms are trembling; sweating; becoming irritable or upset; going pale; lips tingling; blurred vision; confusion; tiredness and dizziness or a fast heartbeat. You should recognise the warning signs and act quickly, and tell your friends and family what to look out for.
To treat a hypo you should drink something sugary or 15-20g of a quick-acting carbohydrate such as 8 jelly beans or 4-6 glucose tablets, and follow on with some slow-release carbohydrate such as a banana or sandwich. You should recheck your blood glucose level after 10-15 minutes to make sure it has normalised. If someone has a severe hypo and has become unconscious, then contact the emergency services immediately.
High Glucose
Glucose levels may go high due to illness, inactivity, missed treatment or higher carbohydrate intake. People with type 1 diabetes need to adjust their insulin levels in response to high glucose levels, otherwise, Diabetic Ketoacidosis (DKA) can occur. DKA is when your body doesn’t have enough insulin so it can’t use glucose as energy, and starts burning fat instead. The fat tissue produces an acidic substance called ketones, which if left untreated can build up in the bloodstream and can make you very ill.
Symptoms of DKA are normally extreme thirst; urinating more; tiredness; confusion; stomach pain; vomiting and/or diarrhoea; strange taste and breath that smells like pear drop sweets. If you have type 1 diabetes, high glucose and tested positive for ketones then you should contact your diabetes team immediately (see sick day rules).
Both hypoglycaemia and DKA are serious conditions that need immediate action to prevent you from becoming very unwell. Testing your blood glucose levels regularly helps prevent both hypos or DKA.
To find out more about short term complications, register for our Understanding Type 1 e-learning course. There is also a list of additional resources about short term complications below.
Advanced Search
Resource type -
Language -
Type of diabetes -
A low blood sugar, also called hypoglycaemia or a "hypo" is where the level of sugar (glucose) in your blood drops too low. In this video, healthcare professionals describe what hypoglycaemia is; how it is treated and what can cause it. You will also hear from people with diabetes describe their own…
You must do something as soon as you notice symptoms of a hypo, or if a blood test has shown your blood glucose levels (also called blood sugar) is too low. If you don’t act quickly, it could get worse and you could start feeling confused and drowsy.
This resource tells you how to recognise when you have ketones in your blood and how these can cause diabetic ketoacidosis if left untreated.
This resource provides guidance for managing illness when using an insulin pump.
This resource explains what to do if you are unwell and have type 1 diabetes.
This page explains what hypoglycaemia is and provides detailed information on the causes and symptoms of a hypoglycaemic episode (a 'hypo') and what you should do if you have one.
This course provides information about continuous glucose monitoring and the Freestyle libre. It is aimed at anyone diagnosed with type 1 diabetes that is using or would like to start using a continuous glucose monitor.
Flowchart for managing large (high) ketones when using a hybrid closed loop.
The Association of British Clinical Diabetologists (ABCD) sick day flowchart for users of hybrid closed loop.
TREND UK leaflet explaining what hypoglycaemia is, the warning signs of a hypo and how to treat it.
Sick day rules flowchart for insulin pump therapy users.
Flowchart for managing trace (low) ketones when using a hybrid closed loop.
