Hypoglycemia occurs when blood glucose levels fall below 4 mmol/L (72mg/dL).

Whilst many of us do think of diabetes as being a problem of high blood sugar levels, the medication some people with diabetes take can also cause their sugar levels to go too low and this can become dangerous.

What is hypoglycemia?

Hypoglycemia occurs when the level of glucose present in the blood falls below a set point:

  • Below 4 mmol/L (72mg/dL)

Being aware of the early signs of hypoglycemia will allow you to treat your low blood glucose levels quickly – in order to bring them back into the normal range.

It is also recommended to make close friends and family aware of the signs of hypoglycemia in case you fail to recognise the symptoms.

What are the symptoms of hypoglycemia?

The main symptoms associated with hypoglycemia are:

Symptoms of hypoglycemia can also include:

Who is at risk of hypos?

Whilst low blood sugar can happen to anyone, dangerously low blood sugar can occur in people who take the following medication:

If you are not sure whether your diabetes medication can cause hypos, read the patient information leaflet that comes with each of your medications or ask your doctor.

It is important to know whether your diabetes medication puts you at risk of hypos.

What are the causes of hypoglycemia?

Whilst medication is the main factor involved in hypoglycemia within people with diabetes, a number of other factors can increase the risk of hypos occurring.

Factors linked to a greater risk of hypos include:

You can take steps to minimise the risk of these factors causing hypos.

How is hypoglycemia diagnosed?

Hypoglycemia is detected by measuring blood sugar levels with a glucose meter. Any blood glucose level below 4.0 mmol/L indicates that the individual has hypoglycemia. Urine tests do not detect hypoglycemia.

If taking a blood test is not possible or would take too much time, it may be better to treat the hypo straight away.

How do I treat hypoglycemia?

A mild case of hypoglycemia can be treated through eating or drinking 15-20g of fast acting carbohydrate such as glucose tablets, sweets, sugary fizzy drinks or fruit juice.

Some people with diabetes may also need to take 15-20g of slower acting carbohydrate if the next meal is not due.

A blood test should be taken after 15-20 minutes to check whether blood glucose levels have recovered. Severe hypoglycemia may require an ambulance, for example if loss of consciousness occurs or a seizure persists for more than 5 minutes.

Severe hypos can be treated with glucagon if a glucagon injection kit is available and in date.

How serious is hypoglycemia?

Hypoglycemic episodes can range from mild to severe.

Mild hypoglycemia can usually be treated by the individual and are to be expected to some degree in people on insulin. Mild hypos are not associated with significant long term health problems unless they are occurring very regularly or for long periods of time.

Severe hypoglycemia, however, will require treatment from someone else and may require an ambulance. Severe hypos can lead to immediate danger if not treated immediately. Whilst rare, severe hypos can potentially lead to coma and death.

Do symptoms always occur before hypoglycemia?

Most people experience some warnings before the onset of hypoglycemia. However, some diabetics may experience little or no warning before the onset of sudden or severe hypoglycemia.

An impaired ability to spot the signs of hypoglycemia is known as loss of hypo awareness (or hypo unawareness ).

Preventing hypoglycemia

The key to preventing hypos is understanding why hypos occur and then taking actions to stop this happening. If you know that a hypo is likely to occur soon, carbohydrate can be taken to raise sugar levels and prevent the hypo.

If your doctor is happy for you to adjust your medication doses, you can also lower your dose during or following certain activities (eg exercise or after having alcohol) to prevent a hypo occurring.

Testing blood sugar levels regularly can help you to understand when your sugar levels are dropping too low.

Your diabetes health team can help you with making changes to your diabetes management.

Are hypos catching you without warning? Join the Hypo Awareness Program for a comprehensive guide towards recovering your hypo awareness »

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