No. Values are sent to TestWell's server for the lookup, matched against the reference catalog and returned; they are not saved, and the usage log records only that the tool was used and how many values were checked — never the markers or numbers.

Why does the flag differ from my lab report?

Each lab publishes its own reference intervals, so the same value can sit inside one lab's range and just outside another's. This tool uses the typical ranges major US labs use; when they disagree, the range printed on your report is the one that applies to your result.

Is an out-of-range value a diagnosis?

No. Ranges are set so about 95% of healthy people fall inside, which means 1 in 20 healthy results lands outside by definition. The explainer shows what a result commonly means and what clinicians usually check next; a clinician interprets it with your history and exam.

What formats can I paste?

One result per line: a marker name, then the value, then an optional unit — "TSH 5.2 mIU/L", "Ferritin: 12 ng/mL", "LDL 131 H". Trailing reference ranges in parentheses and H/L flags are ignored. Up to 40 lines at a time.

Free tool

Lab Results Explainer: Paste Your Values, See What's High or Low

The short answer

Paste results one per line ("TSH 5.2 mIU/L", "Ferritin: 12"), add your sex and age if you like, and each value is checked against TestWell's physician-reviewed reference catalog of 130+ markers. Out-of-range values show the reviewed explanation of what high or low commonly means, when to retest, and cited sources. Values are processed on request and never stored.

Markers: 130+
Bands: Sex · age specific
Storage: None
Cost: Free

Your results — one per line

Sex (optional)Age (optional)

Nothing recognized yet ·

Values are checked on request and not stored. Educational only — your lab report's printed range takes precedence, and a clinician interprets results with your history.

Results appear here: each value flagged low, normal or high against the reviewed reference band for your sex and age, with what an out-of-range result commonly means and what clinicians usually check next.

How does the explainer decide what's high or low?

Every value is matched to a marker in TestWell's reference catalog — 130+ biomarkers with reviewed ranges from Quest, Labcorp, Mayo Clinic Laboratories and the AACC — and compared with the most specific band for the sex and age you enter. A result above the band is flagged high, below it low. The explanation text for an out-of-range value is the same reviewed copy shown on the marker's page; nothing is generated on the fly.

Two limits worth knowing: reference ranges describe where about 95% of healthy people fall, so a mild excursion is common and often meaningless on its own; and your lab's own printed range is calibrated to its analyzers, so it takes precedence when the two disagree.

What are the reference ranges for the most-checked markers?

Adult bands from the reviewed catalog; sex-specific where the catalog splits them. Every marker links to its full table and sources.

Marker	Reference range	Interpretation pages
Glucose	age 18+, fasting: 70.0 – 99.0 mg/dL	High · Low
Hemoglobin A1c	age 18+: 4.00 – 5.60 %	High · Low
Total Cholesterol	age 18+: 125 – 200 mg/dL	High
LDL Cholesterol	age 18+: 0.000 – 100 mg/dL	High
HDL Cholesterol	Male, age 18+: 40.0 – 100 mg/dL · Female, age 18+: 50.0 – 100 mg/dL	High · Low
Triglycerides	age 18+, fasting: 0.000 – 150 mg/dL	High
TSH	age 18+: 0.450 – 4.50 mIU/L · age 18+, pregnancy: 0.100 – 4.00 mIU/L	High · Low
Free T4	age 18+: 0.820 – 1.77 ng/dL	High · Low
Vitamin D, 25-Hydroxy	age 18+: 30.0 – 100 ng/mL	High · Low
Vitamin B12	age 18+: 200 – 1100 pg/mL	High · Low
Ferritin	Male, age 18+: 24.0 – 336 ng/mL · Female, age 18+: 11.0 – 307 ng/mL	High · Low
Hemoglobin	Male, age 18+: 13.5 – 17.5 g/dL · Female, age 18+: 12.0 – 15.5 g/dL	High · Low
White Blood Cell Count	age 18+: 4.50 – 11.0 10^3/uL	High · Low
Platelet Count	age 18+: 150 – 450 10^3/uL	High · Low
Creatinine	Male, age 18+: 0.740 – 1.35 mg/dL · Female, age 18+: 0.590 – 1.04 mg/dL	High · Low
eGFR	age 18+: 60.0 – 120 mL/min/1.73m2	Low
ALT	Male, age 18+: 7.00 – 55.0 U/L · Female, age 18+: 7.00 – 45.0 U/L	High
AST	Male, age 18+: 8.00 – 48.0 U/L · Female, age 18+: 8.00 – 43.0 U/L	High
Potassium	age 18+: 3.50 – 5.00 mmol/L	High · Low
Sodium	age 18+: 135 – 145 mmol/L	High · Low
Calcium	age 18+: 8.60 – 10.3 mg/dL	High · Low
Total Testosterone	Male, age 18+: 264 – 916 ng/dL · Female, age 18+: 15.0 – 70.0 ng/dL	High · Low
Estradiol	Male, age 18+: 10.0 – 40.0 pg/mL · Female, age 18+, varies by cycle phase: 15.0 – 350 pg/mL	High · Low
Cortisol AM	age 18+, drawn 6–10 AM: 6.20 – 19.4 mcg/dL	High · Low
hs-CRP	age 18+: 0.000 – 3.00 mg/L	High

What does a high or low result mean, marker by marker?

Detailed interpretation pages — common causes, symptoms, what clinicians check next — for the markers people ask about most.

Frequently asked questions

Which biomarkers does this tool cover?

Which tests give you these numbers?

Physician-authorized, drawn at Quest, Labcorp or BioReference. Results in 1–3 business days for most tests.