Modern pathology testing is extremely accurate. It is one of the most regulated areas of healthcare and laboratories are accredited through the National Association of Testing Authorities (NATA).
However, accuracy also depends on getting the right sample in the first place. You play an important role in this. Read on for tips on helping your healthcare providers get the right results.
Provide all relevant information
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 health. 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.
If you have a family history of a certain condition, make sure to let them know. The reliability of your test results depends on having the right information.
Questions to ask
Find out why your 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:
Your doctor is the best person to answer these questions. It’s a good idea to take notes of what they say. If you forget anything that you’ve been told you may find the answers on this website.
Some tests require preparation
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 of day.
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 or not you have prepared properly, check with the person taking your sample – the nurse or the collector at the laboratory’s collection centre (phlebotomist).
Some tests 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 because 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 Helicobacter pylori you must stop taking antibiotics, bismuth medication and proton pump inhibitors.
Having the test
Don't hesitate to let the person know who is taking the sample if you have had a previous bad experience. For example, if you have felt light-headed or have fainted while having your blood drawn, ask to be allowed to lie down for the procedure. You can expect that the health professionals responsible for collecting the sample have been trained to be sensitive to the needs of apprehensive patients and people with special needs.
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Information is prepared and reviewed by practising pathologists and scientists and is entirely free of any commercial influence.