Our Commitment

Our information is written by practising Australian pathologists and senior laboratory scientists. We also comply with the HONCode Standard for trustworthy health information.

Our Commitment

Our information is written by practising Australian pathologists and senior laboratory scientists. We also comply with the HONCode Standard for trustworthy health information.

Your Role

You play an important role in ensuring you get most benefit from your tests and that your test results are accurate. It is important you do everything you can to make sure the information you provide is correct and that you follow instructions closely. 

Provide all relevant information

 Effective communications between you and your healthcare team is essential. The choice of tests your doctor makes will be based on your clinical history and symptoms.   Tell them everything you think may have a bearing on your healthcare.  You may feel uncomfortable or embarrassed talking about some aspects of your health in the consulting room – but your diagnosis depends on you being honest and open with them. 

Give them your complete personal, medical and family history and tell them about any medications that you are taking at the time of testing, including herbal remedies and supplements, as these can affect the results. You also may be asked about the amount of alcohol you drink and if you smoke. Providing complete, accurate information is essential to the reliability of your test results.

Ask  questions

 Find out why tests need to be done, how they will be done, and what your doctor expects to learn from them. Make some notes to take along if this helps.  Ask:

  • Why does this test need to be done?
  • How could it change the course of my care?
  • What do I need to know or do before the test? (See Follow instructions below.)
  • What factors can affect the results?
  • What happens during the sample collection?
  • How much will it hurt or cause inconvenience?
  • How much will the test cost? Is it covered by Medicare or private insurance?
  • How long will it be before my results are available?
  • Where do I need to go to take the test?
  • What does an abnormal result mean?
  • Will an abnormal result mean I need further tests?
  • What course of action may be next, after the test?

 Your doctor is the best person to answer these questions. Take notes of what they say, if this helps.  If you forget anything that you’ve been told you may find the answers on this website. 

People who need special help

Children, people who have a disability and the elderly may need special help when having a sample taken. Please see Coping with discomfort and anxiety.

 Follow instructions

 Pathology tests are only as good as the samples on which they are performed.  Most tests are straightforward and require no preparation but others require you to make some changes.  Some tests require you to fast, to stop eating certain foods or to stop taking medications or supplements. Some require you to give a sample at a specific time. 

Be sure to check with your doctor or their medical practice about their instructions rather than relying on the information on this or other web sites, as procedures can differ between testing laboratories. 

If you have any doubts about whether you have prepared properly, check with the person taking your sample – the nurse or the collector at the laboratory’s collection centre (phlebotomist). For a brief outline on the way samples are collected see How samples are collected.

 Examples of test preparation


Some tests such as blood lipids (cholesterol and triglycerides) and glucose require you to fast before you give the sample because food can affect the results.  In the first few hours after you eat, many chemicals in your blood undergo changes. 

Changes can also occur if you don’t eat for an extended period.  So, fasting for too long can also affect the results. In most situations, fasting means not eating for between three and 12 hours.  Samples for fasting blood tests are often collected in the morning after an overnight fast.  For most fasting tests you are advised to drink water as normal. Being dehydrated can also affect results.  However, some tests require you to stop drinking water. 


The types of food you eat can be important when preparing for some tests. Some tests require you to avoid certain food, others require you to eat a low or high fibre diet.

Smoking and alcohol
Some tests require you to stop smoking or stop drinking alcohol.
Medications and/or supplements

Some tests require you to stop taking medications and/or supplements. This must be done under your doctor’s supervision. For example, allergy testing means stopping antihistamines; the Hydrogen Breath Test requires you to stop taking antibiotics and laxatives; and if you are having a test for H. pylori you must stop taking antibiotics, bismuth medication and proton pump inhibitors.

When you have a pathology test it’s usually either because your GP or specialist doctor has requested it, or you are in hospital and tests are needed as part of your diagnosis, treatment or care.

Today, laboratory testing is performed in many different settings, from the large, highly automated central laboratory that performs thousands of tests a day to your own home, where you might do a pregnancy test or monitor your blood glucose levels.

Samples can be blood, urine, a throat or nose swab or a piece of tissue - even a biopsy taken while you are under anaesthetic on the operating table.  Once collected, they must be delivered to the lab. Depending on the type of tests you are having your samples could go to any one or more of a number of different types of labs.

All laboratories are not the same for the simple reason that not all tests are the same. Just as tests vary in complexity, and the technology needed to perform them, so too laboratories vary in their complexity, the numbers and types of tests they can perform, the professionals who staff them and the technology they have available.

Private laboratory

In Australia a large proportion of laboratory testing is done outside the public hospital system in private pathology laboratories. Most testing requested by family doctors, specialists in private practice and by doctors working in private hospitals, is referred to private pathology laboratories. In the state capitals and larger cities there are big private diagnostic laboratories that are actually not a single lab but a cluster of many specialist labs or departments. They employ hundreds of people – pathologists, scientists, technicians and many support staff. There are also smaller private diagnostic laboratories, especially in regional towns, which are generalists handling the common tests and sometimes a few special tests. These are often one or two person pathology practices with support staff.


Hospital labs run 24-hours, seven days a week and are geared to emergency work as well as the often life-threatening illnesses they see on a regular basis. Tests that are performed include those that are needed in emergency situations (such as markers for heart attacks and tests needed for checking the suitability of blood for transfusion) and those done in large numbers which require automated testing analysers. Hospital laboratories are generally used by inpatients and outpatients for the particular hospital. However, as a patient you may never visit the laboratory unless your doctor asks you to go there to have a sample taken.

Hospital laboratories are usually organised into sections depending on the type of testing to be performed. For example, there are usually sections for microbiology (the study of bacteria and viruses), haematology (the study of blood cells), clinical biochemistry (the study of the chemical composition of the blood), blood transfusion and anatomical pathology (testing of tissue samples).

Smaller laboratories are attached to regional hospitals, spread thoughout most states in Australia.  

Point of Care

Laboratory tests may also be performed at the actual point of care - in other words, where the patient is (at the bedside or in the GP surgery or clinic) rather than in a distant laboratory. Laboratory tests in these places are usually limited to uncomplicated tests. Tests done at the point of care tend to be time-consuming for the personnel involved and relatively expensive compared to laboratory tests, but they are more convenient for patients and provide rapid results.

Point of care testing is increasing as technological advances bring about portable devices that are easy to use and produce immediate results. Examples include blood glucose tests, blood gas monitoring systems and analysers for tests for blood clotting and to detect heart attacks.

Tests performed at the point of care must comply with standards just like those performed in central laboratories (see Laboratory Accreditation article), and proper systems of quality control should be operated. It is expected that point of care testing will continue to develop as new devices become available, in part because they may reduce delays and provide immediate information to doctors, allowing more timely medical treatment.


Some tests are being adapted for use at home as patients take on responsibility for their health care. Common home tests include pregnancy tests and ovulation predictors for women, blood glucose monitors for diabetics and prothrombin-time tests to monitor the doses of drugs that prevent clotting of the blood.

Home tests are usually bought over the counter at pharmacies. Some may require a doctor’s prescription in order to obtain reimbursement. The advantages of home tests include convenience and rapid results.

However, while the devices appear simple it is possible to obtain the wrong results if the instructions that accompany the device or test are not carefully followed. Such instructions include information on the correct storage of strips or other reagents and using the right type of sample whether blood or urine.

It may also be necessary to seek professional advice to understand the significance of a particular result and you should obtain this from your doctor or pharmacist.

Other home tests are available over the internet but users should be cautious about their use since at the moment there is no way to be sure that these devices conform to specific quality requirements. Again, you should discuss the suitability of these tests with your doctor.

Reference laboratory

Tests that are less-commonly performed or that require special equipment or expertise may be referred to a specialist laboratory elsewhere. They are staffed by pathologists and scientists with high-levels of expertise in performing complicated and unusual tests – esoteric tests. Many of these tests require sophisticated and expensive technology.

Our aim is to provide you with information about pathology testing that you can rely on as being accurate, authoritative and independent of commercial or political influences.

Pathology Tests Explained is a not-for profit organiation and is funded by the Australasian Association for Clinical Biochemistry and Laboratory Medicine (AACB), one of pathology’s peak bodies representing many of the professionals who work in laboratories.

It is supported by the Royal College of Pathologists of Australasia (RCPA) whose members write, review and edit much of the website content.

The site is accredited by and complies with the international standards of the Health On the Net (HON) foundation
Who writes the information?
Information on Pathology Tests Explained has been written by practising pathologists and scientists including some of Australia’s leading experts.  All scientific information is directed and coordinated by our Editor in Chief, Dr John Beilby.