Laboratory testing is a medical procedure in which a healthcare provider collects a sample of bodily fluids (such as blood or urine) or body tissue in order to get information about the patient’s health. Lab tests can be used to provide general information about organs or body systems, diagnose or screen for illnesses, and monitor the effectiveness of treatment plans.
What kind of tests can be performed in a lab?Kristin Ferguson2020-07-21T20:56:32-04:00
Lab tests can be performed on many different types of samples. Blood, urine, stool, and saliva are among the most common specimens used in lab tests. Other bodily fluids such as sputum, semen, and cerebrospinal fluid can also be tested, along with tissue biopsies, hair, fingernails, and bone marrow.
What are some things a lab test can diagnose?Kristin Ferguson2020-07-21T20:56:32-04:00
No. Certain lab tests (such as cholesterol tests and triglyceride level tests) do require fasting, as the chemicals and nutrients in your foods can affect test results. However, not all lab tests require fasting. Your healthcare provider will let you know which factors might skew the results of your specific lab test, so you can prepare accordingly.
Can I get a lab test without a doctor’s order or prescription?Kristin Ferguson2020-07-21T20:56:32-04:00
Maybe. In states with Direct Access Testing, individuals are allowed to order their own lab tests directly, without the need for a doctor’s order or prescription. Laws and restrictions vary by state, and Direct Access Testing is not available in all areas. Does your state perform Direct Access Testing? Learn more here.
The cost of lab testing can vary dramatically, and may depend on factors such as the type of test being performed and the patient’s insurance plan. For patients with health insurance coverage, the copay for a lab test could be as low as $0; for patients without insurance, a lab test could range from hundreds to thousands of dollars.
With some lab tests, it is possible for healthy individuals to receive varying results. These variations can be caused by factors such as sex, race, weight, and medical history. The same individual could even receive different test results on different days, depending on factors like stress, sleep quality, and diet.
In other words, there is often no singular “normal value.” Instead, there is a range of normal values called the “reference range;” for example, 16–30 mg/dL (milligrams per deciliter). In general, healthy individuals will have results that fall somewhere within this reference range.
Each lab test has its own reference range. When you receive your results paperwork, it should show the reference range as well as your individual results.
It is important to understand exactly what is being tested, and to ask your healthcare provider for clarification if you are having trouble understanding your results. It doesn’t matter whether you’re reading BUN test results, TSH test results, or another test result entirely—the key is to understand the reference range and see where your results fall on that scale.
In addition to displaying a reference range and your unique result, lab paperwork sometimes shows phrases such as “negative” or “normal” (which means the disease being tested was not found) and “positive” or “abnormal” (which means the disease being tested was found).