Diabetes and Hypoglycemia

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

Whilst many of us think of diabetes as being a problem of high blood sugar levels, the medication some people with diabetes take medication that 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:

  • Sweating
  • Fatigue
  • Feeling dizzy

Symptoms of hypoglycemia can also include:

  • Being pale
  • Feeling weak
  • Feeling hungry
  • A higher heart rate than usual
  • Blurred vision
  • Confusion
  • Convulsions
  • Loss of consciousness
  • And in extreme cases, coma

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:

  • Sweating
  • Fatigue
  • Feeling dizzy

Symptoms of hypoglycemia can also include:

  • Insulin
  • Sulphonylureas (such as glibenclamide, gliclazide, glipizide, glimepiride, tolbutamide)
  • Prandial glucose regulators (such as repaglinide, nateglinide)

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:

  • Too high a dose of medication (insulin or hypo causing tablets)
  • Delayed meals
  • Exercise
  • Alcohol

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.

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).