Hypoglycaemia (or hypo) means ‘low glucose’ and we define this as a drop in blood glucose level to less than 3.6mmols/L. Hypoglycaemia is part of everyday life when living with diabetes because we are aiming for ‘normal’ glucose levels. In someone without diabetes, the body keeps the blood glucose levels within narrow targets, by constantly readjusting how much insulin and glucagon are produced.
In type 1 diabetes where insulin is injected (using either an insulin pump or pen injections), it is normal to have hypoglycaemia every now and then. The important thing is that you learn how to treat the hypoglycaemia quickly and effectively.
- Too much insulin given - this could be too much insulin or insulin given at the wrong time.
- The wrong insulin given e.g. long-acting insulin instead of fast-acting insulin.
- Too much insulin for the food that has been eaten or a missed meal.
- Physical activity or exercise – increased glucose use during and after exercise and therefore an increased risk of hypoglycaemia.
- Drinking alcohol or taking drugs.
- Insulin stacking (where ‘correction’ doses of insulin are given very close together).
- Illness – specifically gastroenteritis or tummy upsets.
- Variable insulin absorption e.g insulin injected into fatty lumps (lipohypertrophy).
Hypoglycaemia can be detected using continuous glucose monitoring (CGM) devices (including Dexcom, Medtronic Simplera Sync or Libre sensors) which measure the glucose level in the interstitial fluid just under the skin. This might be referred to as sensor glucose. Alternatively, a finger prick blood glucose test (SMBG) measures the glucose level in the blood (blood glucose). A finger prick blood glucose test is recommended if the sensor glucose does not match the child’s symptoms.
The body does not like the glucose level to drop too low and will produce sensations that are warning symptoms that the glucose level might be dropping. Parents and carers are more likely to notice symptoms such as irritability and behavioural changes. In young children, behavioural changes such as irritability, agitation, quietness, and tantrums may be prominent.
Symptoms are divided into 2 types – symptoms caused by the body trying to raise the glucose level (known as autonomic or adrenergic symptoms) and those caused by the effect of the low glucose on the brain (neuroglycopenic symptoms).
Symptoms of hypoglycaemia may not always be recognised by the person who has diabetes, particularly if they are focused on something else, for example when distracted with schoolwork or playing with friends. Not everybody will have the same symptoms when their glucose level drops and how your child feels when hypo will depend on how the brain copes with a low glucose level and how the body reacts.
The effect of low blood glucose levels on the brain includes:
- difficulty concentrating
- weakness, dizziness
- double or blurred vision
- drowsiness
- odd behaviour, poor judgement, or confusion
- in extremes, seizure and coma.
The effect of the body trying to correct the low glucose level includes:
- heart beating fast, shaking, feeling anxious
- heart palpitations
- numbness in lips, fingers or tongue
- sweating
- hunger, feeling sick.
Hypoglycaemia – mild/moderate
The severity of hypoglycaemia can be described as mild, moderate or severe. For adults, the difference between mild and moderate is whether help is needed from another person. In children however, most hypo episodes require an adult to help ensure that the hypo is treated. The aim is to restore the glucose level back to a normal level. To treat mild/moderate hypoglycaemia, follow the instructions in the table below.
| Multiple Daily Injections | Pump therapy (not hybrid closed loop) | Hybrid closed loop pumps & in auto mode | |||||||||||||||||||||||||||||||||||||||||||
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Step 1 Confirm hypoglycaemia |
Sensor or blood glucose 3.5 mmols/L or less and child conscious/able to swallow If a child says they feel hypo but with a 'normal' sensor glucose, perform a finger prick to confirm hypoglycaemia |
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Step 2 If hypo and child conscious, give hypo treatment |
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Check pump to confirm insulin delivery suspended
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Step 3 Recheck/Retest sensor or blood glucose |
Either blood glucose after 15 minutes or sensor glucose after 20 minutes If glucose level 3.6 or above, no further action required If glucose remains 3.5 mmols/L or less, give 2nd hypo treatment |
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Step 4 Give 2nd Hypo treatment if hypoglycaemic |
Repeat hypo treatment using quantities above. | Repeat hypo treatment using quantities above. | Repeat hypo treatment using quantities above. |
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Step 5 Recheck/Reset |
Either blood glucose after 15 minutes or sensor glucose after 20 minutes If glucose remains 3.5mmols/L or less |
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Step 6 Further treatment if still hypoglycaemic |
Give 15 grams long-acting carbohydrate snack (without insulin) | Suspend pump and repeat hypo treatments every 15 mins until glucose rises above 5.6mmol/L or the CGM arrows point upwards | Repeat hypo treatments every 15 mins until glucose rises above 5.6 mmols/L or the CGM arrows point upwards |
The amount of glucose required to treat hypoglycaemia will depend partly on the weight/age of the child. Use this table to find the right amount of hypo treatment.
| 2g Glucose | 3g Glucose | 5g Glucose | 8g Glucose | 10g Glucose | 15g Glucose | |
|---|---|---|---|---|---|---|
| Lift Glucose Shot | 10mls | 10-15ml | 20mls | 30ml | 40mls | 60mls |
| Lift Glucose Tablets (1 tablet contains 4g) | 1/2 tablet | - | 1 tablet | 2 tablets | 2-3 tablets | 4 tablets |
| Lucozade Energy Tablets (1 tablet contains 3g) | - | 1 tablet | 2 tablets | 3 tablets | 3-4 tablets | 5 tablets |
|
Dextrosol (1 tablet contains 3g) |
- | 1 tablet | 2 tablets | 3 tablets | 3-4 tablets |
5 tablets |
| Jelly Sweets (average weight) | 3g | 4g | 6g | 10g | 12g | 18g |
Severe hypoglycaemia
In children, severe hypoglycaemia is defined as an event with severe cognitive impairment (including a seizure or loss of consciousness) that requires urgent assistance by another person; or requiring emergency medical personnel; or a visit to the emergency department. When/if this happens, nothing should be given by mouth. Instead, Glucagon (either GlucaGen Hypo Kit or Ogluo prefilled pen) should be injected with the dose calculated based on weight.
- 1 mg for children >25 kg
- 0.5 mg for children <25 kg
If the child is unconscious, place in the recovery position and ring for an ambulance. Continue to monitor the glucose level.
Glucagon Instructional video
Ogluo instructional video
Top tips
- Carry your hypo kit with you. Make sure that your family, friends, teachers, and sports coaches know how to recognise and treat hypos.
- Always treat hypos quickly.
- Be aware of your/your child's hypo syptoms.
- If you are old enough to drive, remember not to drive if you are below 5mmol/L
Emergency mobile: 07940 476 811
Email: uclh.
Further information and fact sheets can be found on our Children and Young People’s Diabetes web page.
Page last updated: 14 January 2025
Review due: 01 January 2027