This page provides information for people with diabetes, about having a hypoglycaemic (low blood glucose) episode.

What is hypoglycaemia?

Hypoglycaemia (known as a ‘hypo’) is when your blood glucose level is less than 4mmol/L. The short saying to help you remember this is ‘4 is the floor’. Hypoglycaemia can happen when you are treated with insulin or some diabetes tablets for the following reasons:

  • Physical activity
  • Too much insulin/tablets
  • Too little food, missed meals
  • Alcohol
  • Hot weather

Sometimes there is no obvious cause.

What are the signs and symptoms of hypoglycaemia?

A ‘hypo’ can be mild, moderate or severe, but must always be treated quickly. Hypoglycaemia warning signs and symptoms vary from person to person. Some people, especially if they often have low blood glucose levels, only have a few symptoms (known as loss of hypoglycaemia awareness).

You may have symptoms such as:

  • Hunger
  • Looking pale
  • Feeling anxious or irritable
  • Tingling of lips and fingers
  • Feeling shaky/dizzy/sweaty

Other people may notice that you are:

  • Uncoordinated/clumsy
  • Not able to speak
  • Irritable
  • Having night sweats

Wear or carry a form of diabetes identification and make sure that other people know what to do if you have a hypo.

How to treat yourself if you have hypo

  1. Stop what you are doing; you need to act immediately to treat a hypo.
  2. Take some fast acting glucose:
  • 5 to 6 dextrose tablets
  • 150 to 190mls Coca Cola® (full sugar)
  • 4 to 5 glucotabs
  • 3 to 4 jelly babies
  • 2 tubes of GlucoGel® – only on prescription from your GP
  • 170 to 220mls pure orange juice

Due to the changing sugar content of Lucozade® and Ribena®, we no longer recommend using this as treatment

3. Check blood glucose level again after 10 minutes

4. If blood glucose level is still less than 4mmol/L, repeat Step 2. If blood glucose level is more than 4mmol/L, move to Step 5.

5. Follow the fast acting glucose with a snack:

  • Half a sandwich
  • Biscuits and milk
  • Fruit
  • Next meal (if due)
  • Cereal

Hypoglycaemia with loss of consciousness

Very low blood glucose levels can cause you to become unconscious. If this happens you must not be given anything by mouth and 999 (Emergency Services) must be called. If you have glucagon prescribed, this is when it should be used. You should be put on your side with your head tilted back (the recovery position).

After the hypo

  • Try to think why you had a hypo, was there an obvious cause? If yes, can you make changes to prevent it happening again?
  • After the hypo, your blood glucose level may be high for several hours due to the action you have taken to treat your low glucose. Also, your body will make anti-insulin hormones in an effort to correct the hypo. Do not worry about this.
  • Hypos should only happen very rarely. If you have repeated hypos, you should contact the diabetes team.

Driving and hypos

  • Keep glucose treatments in the car at all times.
  • Before driving, check your blood glucose, it needs to be more than 5mmol/l and check every 2 hours if a long journey.
  • If you have a hypo while driving, stop the car as soon as possible. Remove the keys to demonstrate you are not in charge of the car, move into the passenger seat, if safe, and treat the hypo as above.
  • You need to wait at least 45 minutes after recovery from a hypo before you can drive.

Please visit for more information.

Contact information

Cheltenham General Hospital

Tel: 0300 422 4266

Gloucestershire Royal Hospital

Tel: 0300 422 8613

Please leave a message with your name, date of birth and contact number. We will aim to return your call will within 48 hours.

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Printable version of this page

Hypoglycaemia GHPI1143 Department: Diabetic medicine Review due: December 2024 PDF, 164.7 KB, 4 pages
Reference number GHPI1143_12_21
Department Diabetic medicine
Review due December 2024