Emergency advice

Diabetic emergency:

High blood sugar? Call 999.

Low blood sugar?

  1. Sit them down.
  2. Give 3 jelly babies/150ml fruit juice.
  3. No improvement? Call 999

What is diabetes?

Diabetes is a long-term medical condition where the body cannot produce enough insulin. Sometimes those who have diabetes may have a diabetic emergency, where their blood sugar level becomes too high or too low. Both conditions could be serious and may need treatment in hospital.

Insulin is a chemical produced by the pancreas (that lies behind the stomach). It regulates the blood sugar (glucose) levels in the body. When someone has diabetes, their body cannot keep the blood sugar level within the normal range. Their level can be higher or lower than normal blood sugar.

There are two types of diabetes:

  • Type 1, known as insulin dependent diabetes.
  • Type 2, non-insulin dependent diabetes.

Someone with diabetes may have items with them which could lead you to suspect that they have diabetes:

  • they may be wearing a medical warning bracelet or necklace.
  • they may be carrying glucose gel or glucose tablets.
  • they may have a smart glucose monitoring device.
  • they could have medication, such as an insulin pen, a special pump or tablets and a glucose testing kit.


This is where the blood sugar level is higher than normal. It may be caused by a person with diabetes who has not had the correct dose of medication. They may have eaten too much sugary or starchy food or, they may be unwell with an infection.

Signs and symptoms

Look for:

  • warm, dry skin
  • rapid pulse and breathing
  • fruity, sweet breath
  • excessive thirst
  • drowsiness, leading them to become unresponsive if not treated (also known as a diabetic coma)
  • medical warning jewellery or medication.

What to do

  1. If you suspect hyperglycaemia (high blood sugar), they need urgent treatment. Call 999 or 112 for emergency help and say that you suspect hyperglycaemia.

    • They may be wearing a medical bracelet or medallion, or have a card on them which can alert you to their condition.
  2. While you wait for help to arrive, keep checking their breathing, pulse and whether they respond to you.

    • If they become unresponsive at any point, open their airway, check their breathing and prepare to start CPR.


This is where the blood sugar level is lower than normal. It can be caused by an imbalance between the level of insulin and the level of glucose in the blood. Someone with diabetes may recognise the onset of a hypoglycaemic episode.

Signs and symptoms

Look for:

  • weakness, faintness or hunger
  • confusion and irrational behaviour
  • sweating with cold, clammy skin
  • rapid pulse
  • palpitations
  • trembling or shaking
  • deteriorating level of response
  • medical warning jewellery or medication.

What to do

  1. If you suspect hypoglycaemia (low blood sugar), help the person to sit down. If they have their own glucose gel or glucose tablets, help them take it. If not, you need to give them something sugary, such as an 150ml glass of fruit juice or non-diet fizzy drink; three teaspoons of sugar or sugar lumps; or three sweets such as jelly babies.

  2. If they improve quickly, give them more of the sugary food or drink and let them rest. If they have their blood glucose testing kit with them, help them use it to check their blood sugar level.

    A hypoglycaemic patient, where the low sugar has been remedied by sweets / sweet drink is usually shortlived, and they should have something more substantial to eat to sustain their condition.

    Stay with them until they feel completely better.

  3. If they do not improve quickly, look for any other reason why they could be unwell and call 999 or 112 for emergency help.

  4. Keep monitoring their breathing and level of response while waiting for help to arrive.

    • If they are not fully alert, don’t try to give them something to eat or drink as they may choke.
    • If they become unresponsive at any point, open their airway, check their breathing and prepare to give CPR.

Browse our first aid products:

CPR masks and face shields

CPR masks and face shields

Shop now


Our training courses:

First aid courses

First aid courses


Related first aid advice

How to do CPR on an adult

If an adult is unresponsive and not breathing normally, you need to call 999 or 112 for emergency help and start CPR straight away. Learn what to do.

How to do the primary survey

Use the primary survey to quickly assess the situation and check the casualty for injuries or conditions that could be immediately life threatening. Find out what to do.

Who should I call?

At some point in their life, most people will witness or be involved in an accident or medical emergency. Knowing what to do and when you should call the emergency services can potentially save lives.

St John Ambulance volunteers providing support