Hypoglycaemia

When your blood sugar falls too much, you have hypoglycaemia or a ‘hypo’. Read more about what happens with hypos and what you can do to avoid them.

What is hypoglycaemia?

If you have Type 1 diabetes then you’ll be on insulin injections. The aim of your insulin treatment is to lower blood sugar levels. Ideally, they should be as low as those of someone without diabetes.

Testing your blood sugar (glucose) level is an important part of your daily routine, to check that it is at an acceptable level.

Sometimes, your blood sugar can fall below the normal level. There are several reasons why this may happen: the insulin treatment itself, vigorous exercise or changing meal times. All these things can sometimes cause hypoglycaemia or 'hypo'. Blood sugar is considered low when it is below 4 mmol/l.

If you have a hypo, you may have a variety of symptoms, which are described below. These symptoms can act as warning signs that you are about to have a hypo. If you know what they are and are aware of them, you can takes steps to stop the hypo from happening.

Experiencing hypoglycaemia

What does it feel like to have a hypo or hypoglycaemia? You will probably have some of these symptoms:

You may feel sweaty or shaky
You may feel anxious or dizzy
You may lose your concentration
You will probably turn pale.

You may not have all these symptoms, maybe only some of them. Low blood sugar feels different to different people. What matters is that you learn to recognise your own warning signs of low blood sugar.

If you feel the signs of lowblood sugar

If you feel you have low blood sugar, you should eat or drink something that contains sugar right away. For example, your doctor may have suggested you take 10-20 grams of "fast-acting" sugar. These are some ways you could get that sugar:

Take 4-6 lumps of sugar
Take 4-6 boiled sweets
Drink 200 ml of orange juice

If you don't feel better after 15-30 minutes of taking the fast-acting sugar, test your blood sugar. If it’s still low, take more fast-acting sugar. If you don’t do this, your blood sugar may become too low for you to be able to help yourself. Once you’re feeling better, you can eat your regular meals and snacks as usual.

Teach your friends

It could happen that your blood sugar drops so low that you're too confused to help yourself. That's why it's important to teach your friends and relatives to help you if they need to.

The main things to tell them are:

They should help you take fast-acting sugar (such as sugar lumps, sweets, fruit juice)
If your blood sugar becomes so low that you pass out, they should give you an injection of glucagon and quickly call an ambulance
When you wake up, you'll need a snack such as some juice and a sandwich.

You may get low blood sugar if:

You miss or delay a meal or simply don't eat enough
You exercise more than usual
You take too much insulin
You drink too much alcohol.

Sometimes people feel different signs of hypoglycaemia or “hypo” when:

They change their insulin dose
They change the number of insulin injections
They change to a different insulin.

Bear this in mind if you do change your insulin treatment.

Blood sugar near normal

Few people with diabetes can avoid episodes of low blood sugar completely. In some ways, hypoglycaemia happens because you are trying to keep your blood sugar near to normal. The best way to help yourself is to learn to recognise your own warning signs. Take action right away when you feel a hypo coming.

Tips for dealing with hypoglycaemia

Always carry fast-acting sugar food or drink with you
Always carry your diabetes ID card with you
Tell those around you how they can help if your blood sugar is low
Test your blood sugar regularly
Act on your blood sugar readings by adjusting your insulin dose, exercise and diet accordingly
If you decide to drink alcohol, remember to go easy and to eat snacks while you're drinking. This helps to keep your blood sugar in the target range
If you think your blood sugar is low, don’t drive a car. You risk passing out at the wheel if you have a hypo while driving.

Hypoglycaemia: a summary

A hypo occurs when blood sugar is too low - below 4 mmol/l
There are various symptoms of hypoglycaemia
Each person experiences hypos in different ways
It’s important to learn to recognise your own warning signs of a hypo
Friends and family should know what to do if you have a hypo and can’t help yourself.

INS/005/0809

Last updated: August 2009