How We Research and Source Our Content

LabDirectories.com publishes educational guides about laboratory testing. Every guide is written to answer a specific question a reader may have about a test, and is reviewed for sourcing accuracy before it is published.

We source medical and scientific information only from reputable public health and clinical organizations, including the U.S. Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), the National Library of Medicine (MedlinePlus), and the U.S. Food and Drug Administration (FDA). Each guide lists the specific sources used.

Our writers follow a consistent editorial checklist: confirm the topic against at least two authoritative sources, describe what a test measures in plain language, explain who typically orders it, and note that reference ranges vary between laboratories.

We do not provide medical advice, diagnosis, or treatment, and we do not give dosing or medication guidance. Reference ranges and clinical guidance vary between laboratories and change over time, so readers should always confirm their own results and care with a qualified healthcare provider.

Guides are reviewed periodically and updated when guidance or testing options change. Each guide shows the date it was last reviewed. If you spot an error or an outdated source, please contact us and we will review it.

Pricing and availability shown on test and location pages come from our testing partners and are presented as typical self-pay ranges. Final prices are confirmed at checkout.

We may earn commissions from affiliate links to testing partners. This does not influence the educational content we publish, and it does not change the price a reader pays.

For each guide, we identify the specific question being answered, gather current public guidance, and write in plain language that does not assume medical training. We separate well-established facts from areas where guidance varies, and we avoid making diagnostic claims.

When a source is updated or withdrawn, we revisit the guide and revise it, and we note the date of the most recent review so readers know how current the information is.