Which lab tests actually help — and which don't?

How do I read the ratings?

Every test on these pages gets one of four labels:

• Guideline-backed — a major clinical guideline recommends it for this purpose.
• Useful in specific situations — worth it when particular symptoms or findings point to it.
• Limited evidence — some research, but too thin or mixed to rely on.
• Not validated / not recommended — there's no good evidence it means what it claims, or medical societies advise against it.

A rating is about one specific use. The same test can be guideline-backed for one question and useless for another — CA-125 is a good example.

Why do some tests come back "normal" when I feel terrible?

Because most chronic conditions in this cluster — endometriosis, adenomyosis, hEDS, POTS — aren't diagnosed with blood tests at all. They're diagnosed from your history, an exam, imaging, or a stand or tilt test. Basic labs are still worth doing, because they rule out things that look similar and are treatable, like anemia, thyroid disease or celiac disease. But a clean panel is information, not a verdict on whether you're sick.

What's the difference between a lab being "certified" and a test being "validated"?

In the US, clinical labs are certified under CLIA, which checks that a lab measures things accurately and consistently. CLIA doesn't check whether a test means anything for your health. Most functional medicine panels are lab-developed tests that never go through FDA review of what the results mean. In March 2025 a federal court struck down the FDA rule that would have started regulating these tests, so that gap remains. [1]

Where should I start?

• Endometriosis & adenomyosis
• Hypermobility, POTS & MCAS
• Gut symptoms
• Fatigue
• Functional tests