Understanding Lab Test Results

A common challenge around the world is understanding lab test results: Doctors sometimes do not explain this sufficiently and patients can feel rather stressed. This article will help put it into perspective:

When you consult a doctor because you are ill or when you go for a routine checkup, the doctor will perform laboratory tests as part of the diagnostic process or as part of the checkup. Even with numerous resources available, such as FDA guidelines on lab tests, the test results may be confusing for laypeople. Fortunately, there are a few guidelines that will help you to understand the basics of what to expect when ordering a lab test.

The Importance of Lab Tests

Lab tests are important tools for diagnosis. If you are sick, the doctor will perform some tests to determine what is causing the illness so that you get the right medicine. If you have an ongoing illness the doctor uses lab tests to determine if the treatment is working. If it’s a routine checkup the doctor will use the lab tests to determine how you are doing generally in terms of blood sugar, cholesterol levels, etc.

How Long to Wait for Results?

Some tests can provide instant results. Others can be taken to a nearby lab and provide results within a day. Other tests may take a number of days or even weeks if they are sent to a special lab. Request that the doctor’s office call you as soon as the results are available.

What the Results Mean

Positive or Negative. Some lab tests request to know whether you have a particular problem or not. Such tests bring “positive” or “negative” results. “Positive” means the lab found whatever the doctor was testing for. For example, if the doctor performed a pregnancy test, positive means you are pregnant. “Negative” means the lab did not find what the doctor was testing for.

There are times when such tests may give an “inconclusive” result. It means that there is no clear “positive” or “negative” answer based on your blood or urine sample. The doctor may follow this with a repeat of the test or test for something different.

Reference Ranges. There are tests that do not give a clear “yes” or “no” result. Instead, they show numbers, for example, cholesterol levels and blood sugar levels. These are compared to a healthy range, so your numbers may be higher or lower than the healthy range. From there the doctor will determine whether you need treatment or not.

False Positives and Negatives. Sometimes lab results give false positives or false negatives. A false positive says you have a certain illness when you actually don’t have it. A false negative will say you don’t have the condition when in actual fact you do. False results are caused by certain factors such as some foods, intense physical exercise, engaging in sex, taking certain drugs, colds or infections and even sunburn. If the doctor is convinced that the result is false, he/she will do the test again or run a different test. If you do not believe the results, ask the doctor to repeat the test or to perform a different test.

Abnormal. Sometimes the results come back as “abnormal” if your result is just outside the reference range. This does not necessarily mean you have a problem.

Tips for Lab Tests

Before taking a test, remind your doctor about a preexisting health condition or medications that you are taking, that may affect the result. Keep a copy of your results in a file in case you need them in the future especially if you change doctors.

If you are given instructions to follow before the test, such as fasting, be honest if you failed to follow the instructions. That way the doctor may choose to reschedule the test so that you avoid false negatives or false positives.

Ask your doctor why exactly you are doing the test and what exactly the results mean and whether the test is accurate.

If you are worried about your results, make an appointment and discuss them with your doctor who will help you to understand them.