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Severe Insulin Resistance Service - Hypoglycaemia (‘Hypo’)

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Treat blood glucose levels below 3.5mmol/L as a ‘hypo’ even if you feel well in yourself

Symptoms of hypoglycaemia:

Symptoms of Hypoglycaemia

Hypo symptoms will be different for everybody. You will learn how low blood glucose levels make you feel; although be aware your symptoms may change over time.

Sometimes people find they lose their hypo warning symptoms altogether and if this is the case, it is very important you inform your diabetes team.

Causes of Hypoglycaemia:

  • Missed or delayed meal or snack.
  • Increased activity / unusual activity.
  • Too little carbohydrate at meal or too much insulin.
  • Excessive amounts of alcohol (over 4units in one sitting).
  • Extremes of temperature, such as hot weather or a hot bath.

Sometimes because the body is making so much more insulin to help move the glucose into the cells or more insulin is injected (due to insulin resistance), too much glucose can move into the cells which can also result in a low glucose level (a ‘hypo’ or hypoglycaemia). A blood sugar less than 3.5mmol would be considered a hypo. To avoid this it is important not to go long periods without eating or removing carbohydrate from the diet.

Treat blood glucose levels below 3.5mmol/L as a ‘hypo’ even if you feel well in yourself

Hypo Treatment

Hypo treatment

Night time hypos

It is advised that you test your blood glucose before bed and aim for a reading of 6-8 mmol/l.

You can reduce your risk of hypos by having a snack before bed if;

  • Your blood glucose level is below 6 mmol/l.
  • You have drunk more than the recommended amounts of alcohol or more than usual.
  • You have been particularly active that day or are planning activity through the night
  • You have had a hypo earlier in the day.

If you are having regular hypos in the night it may be a sign that you need less insulin overnight.

Keep some hypo treatment by your bedside. If you have a hypo overnight and are unable to identify the cause, contact your Diabetes Educator to review your insulin dose.

When people go for long periods e.g. over night without eating the body starts to break down fat for energy. As you may not have any fat stores, or your fat stores may be limited then you will use your body’s stores of glucose in the liver for energy when fasting. This is a limited supply and you are therefore more likely to have a hypo or low blood glucose level in the mornings. If you do find you have a low blood glucose level in the morning than you may need to have your medication changed or introduce a snack before you go to bed each night. Please discuss this with your Dietitian or diabetes nurse.

Severe Hypos

If untreated, hypoglycaemia may become much worse and you may become semi-conscious or fully unconscious and will need to be treated by someone else. If you are unconscious you should not be given anything by mouth as you may choke.

Glucagon is an injectable hormone which can be given to you if unconscious to reverse a severe hypo and should bring you round within five to 10 minutes. On recovery, please follow the hypo treatment flow chart. If you do not come round within 10 minutes the emergency services should be called (999).

Glucagon is only available on prescription from your doctor and should only be given by someone who has been trained to give it. Your diabetes team will be happy to provide this training.

Always contact your diabetes team following a severe hypo.

DVLA recommendations for driving

  • If you are taking insulin it is a legal requirement that always check your blood glucose level before driving and it should be above 5.0mmol/L before you start the car.

If your BGL is below 5.0mmol/L you must have a snack of at least 10g of carbohydrate and wait for 15 minutes for your glucose level to rise sufficiently. You should then retest your blood glucose level to ensure you are above 5mmol/L.

  • Test your blood glucose levels at least every two hours on long journeys.
  • If hypoglycaemia develops while driving, stop the vehicle as soon as possible in a safe location, switch off the engine, remove the keys from the ignition and move from the driver’s seat. This is to avoid any suggestion that you are in charge of a car whilst under the influence of any drugs including insulin.
  • Do not resume driving until 45 minutes after blood glucose is 5mmol/L or above.
  • Always keep hypo treatment in your vehicle.

Recommendations on driving may change. Please see the DVLA or the Diabetes UK websites for further information.

If hypos are experienced regularly (more than twice a week) or you have had a severe hypo and the cause cannot be identified, contact your doctor or diabetes team educator.

Contacts/Further information

Severe insulin resistance dietitians (Catherine Flanagan and Lisa Gaff) – 01223 216655

Severe insulin resistance diabetes nurse – 01223 348790 or 01223 768625

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Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151