Blood glucose testing

General Information

Blood glucose testing measures the amount of glucose (sugar) in your blood. Glucose comes from the carbohydrates we eat, and is present in our blood as an energy source. For your body to function normally, blood glucose levels need to be within a certain range; this is controlled by a hormone called insulin.

Some people do not make enough insulin or do not respond fully to the insulin their body makes, which causes their blood sugar levels to be too high (hyperglycaemia). Blood glucose testing, available from your doctor and some pharmacies (or can also be done at home), is one of the most common screening tests used for diabetes.

Diabetes is characterised by persistent hyperglycaemia which is bad for long-term health (see long-term complications of diabetes, below). There are three main types of diabetes: type 1, type 2 and diabetes in pregnancy (gestational diabetes).

Type 1 diabetes

People who do not make any insulin, or very little, have type 1 diabetes. It generally develops before the age of 40.

People with type 1 diabetes need to inject insulin and must monitor their blood glucose levels regularly. The cause of type 1 diabetes is not fully understood.

Type 2 diabetes

Type 2 diabetes develops when your body stops producing enough insulin (insulin deficiency). It can also develop when your body becomes less responsive to the insulin your body does make (insulin resistance). Type 2 diabetes is the most common form of diabetes and often affects people later in life.

Some people with type 2 diabetes can control their blood glucose levels through altering their diet and losing weight. Many people will need to take oral medications to treat type 2 diabetes, and some people will need insulin injections.

You are more at risk of developing type 2 diabetes if you:

  • are of Aboriginal, Torres Strait Island, Asian, Middle Eastern or Pacific Island descent and over 35 years of age
  • are of European descent and are over 40 years of age
  • are overweight, especially if you carry most of your extra weight around your waist
  • do not exercise regularly
  • are over 50 and have high blood pressure
  • have a family history of diabetes
  • are over 65 years of age
  • had diabetes during pregnancy or gave birth to a large baby, weighing more than 4 kg

Gestational diabetes (diabetes in pregnancy)

Gestational diabetes happens when a pregnant woman cannot produce enough insulin to cope with her body’s increased needs during pregnancy. It affects around 4 to 8% of pregnant women, with an increased risk in women over 30 and with diabetes in the family.

Gestational diabetes can sometimes be controlled by dietary changes, but some women need insulin injections. Women should be routinely checked for gestational diabetes in the second trimester. Gestational diabetes should resolve itself after the pregnancy but there is an increased risk of developing diabetes in the future.

Symptoms of diabetes

  • constant thirst
  • passing lots of urine often
  • tiredness
  • weakness
  • extreme weight loss (for type 1 diabetes only)
  • recurrent skin infections
  • fungal and yeast (thrush) infections
  • slow healing wounds and infections
  • numb or tingling hands and feet
  • blurry or hazy vision

Symptoms of type 1 diabetes are often severe and generally lead to a quick diagnosis. However, people with type 2 diabetes generally have milder or no symptoms. Many will be undiagnosed and not realise they have this condition.

Long-term complications of diabetes

If diabetes is not treated, people are at risk of developing complications from having too much sugar in their blood. This is why some people may want to have their blood glucose levels checked, particularly if they have risk factors for developing type 2 diabetes.

When sugar levels remain high in the blood for a long period of time, damage to all the blood vessels in the body occurs. Long-term complications include:

  • kidney disease
  • foot problems
  • impotence
  • increased risk of infections
  • gum and mouth problems
  • nerve damage
  • visual problems
  • an increased risk of heart attack and stroke

These problems usually only show up in people who have had diabetes for a few years, and can be reduced by keeping blood glucose levels and blood pressure in a healthy a range.

See Your Pharmacist or Medical Professional

Diabetes is a condition that must be diagnosed and treated by your doctor. However, many pharmacies offer a blood glucose testing service to screen for diabetes.

Advice for people having a blood glucose test at their pharmacy:

  • blood glucose tests at a pharmacy are usually performed using a portable glucose monitor and testing strips
  • the finger is pricked to produce a drop of your blood, which is placed on a testing strip that contains a chemical
  • the strip is placed in the glucose meter and results appear as a digital display
  • when taking a blood sample, it is important to ensure your finger is clean; food or drink on your skin can interfere with the test
  • some bleeding can happen after the finger is pricked and there is a slight risk of infection

If you have a high blood glucose test result this does not necessarily mean you have diabetes, and you should see your doctor for further tests.

Other medical problems that can cause high blood glucose levels include severe stress and some medications.

More Information

For more information about diabetes, see the link in Related Health Information below.

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