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
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.
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.
- High Activated Partial Thromboplastin Time (aPTT)
- Low Adiponectin
- Low Albumin
- High Albumin/Creatinine Ratio
- High Aldosterone
- Low Aldosterone
- High Alkaline Phosphatase
- High ALT
- High AMH
- Low AMH
- High Amylase
- High Apolipoprotein B
- High AST
- High Basophils
- High Bilirubin
- High BUN
- Low BUN
- High C-Peptide
- Low C-Peptide
- High C-Reactive Protein
- Low C-Reactive Protein
- High CA 19-9
- High CA-125
- High Calcium
- Low Calcium
- High Carbon Dioxide
- Low Carbon Dioxide
- High CEA
- High Chloride
- Low Chloride
- High Copper
- Low Copper
- High Cortisol AM
- Low Cortisol AM
- High Cortisol PM
- Low Cortisol PM
- High Creatine Kinase
- High Creatinine
- Low Creatinine
- High Cystatin C
- High D-Dimer
- Low DHA
- High DHEA-S
- Low DHEA-S
- High Dihydrotestosterone (DHT)
- Low Dihydrotestosterone (DHT)
- High Direct Bilirubin
- Low eGFR
- Low eGFR (Cystatin C)
- High Eosinophils
- Low EPA
- High ESR
- High Estradiol
- Low Estradiol
- High Fasting Insulin
- Low Fasting Insulin
- High Ferritin
- Low Ferritin
- High Fibrinogen
- Low Fibrinogen
- High Folate
- Low Folate
- Low Free PSA %
- High Free T3
- Low Free T3
- High Free T4
- Low Free T4
- High Free Testosterone
- Low Free Testosterone
- High FSH
- Low FSH
- High GGT
- High Glucose
- Low Glucose
- High Haptoglobin
- Low Haptoglobin
- High HDL Cholesterol
- Low HDL Cholesterol
- High HDL Particle Number
- Low HDL Particle Number
- High Hematocrit
- Low Hematocrit
- High Hemoglobin
- Low Hemoglobin
- High Hemoglobin A1c
- Low Hemoglobin A1c
- High Homocysteine
- High hs-CRP
- High IGF-1
- Low IGF-1
- High INR
- Low INR
- High Iron
- Low Iron
- High Iron Saturation
- Low Iron Saturation
- High LDH
- High LDL Cholesterol
- High LDL Particle Number
- Low LDL Particle Size
- High LDL/HDL Ratio
- High Lead (Blood)
- High Leptin
- Low Leptin
- High LH
- Low LH
- High Lipase
- High Lipoprotein(a)
- High Lymphocytes
- Low Lymphocytes
- High Magnesium
- Low Magnesium
- High MCH
- Low MCH
- High MCHC
- Low MCHC
- High MCV
- Low MCV
- High Mercury (Blood)
- High Monocytes
- High Neutrophils
- Low Neutrophils
- High NT-proBNP
- Low Omega-3 Index
- High Phosphorus
- Low Phosphorus
- High Platelet Count
- Low Platelet Count
- High Potassium
- Low Potassium
- High Prealbumin
- Low Prealbumin
- High Progesterone
- Low Progesterone
- High Prolactin
- High Prothrombin Time
- High PSA Total
- High PTH, Intact
- Low PTH, Intact
- High RDW
- High Red Blood Cell Count
- Low Red Blood Cell Count
- High Reticulocyte Count
- Low Reticulocyte Count
- High Reverse T3
- High Rheumatoid Factor
- Low Selenium
- High SHBG
- Low SHBG
- High Small LDL Particle
- High Sodium
- Low Sodium
- High Thyroglobulin Antibodies
- High TIBC
- Low TIBC
- High Total Cholesterol
- High Total IgA
- Low Total IgA
- High Total Protein
- Low Total Protein
- High Total Testosterone
- Low Total Testosterone
- High TPO Antibodies
- High Transferrin
- Low Transferrin
- High Triglycerides
- High Tryptase
- High TSH
- Low TSH
- High tTG-IgA
- High Uric Acid
- High Urine Albumin
- High Vitamin A (Retinol)
- Low Vitamin A (Retinol)
- Low Vitamin B1 (Thiamine)
- High Vitamin B12
- Low Vitamin B12
- Low Vitamin B2 (Riboflavin)
- High Vitamin B6
- Low Vitamin B6
- Low Vitamin C
- High Vitamin D, 25-Hydroxy
- Low Vitamin D, 25-Hydroxy
- Low Vitamin E
- Low Vitamin K1
- High White Blood Cell Count
- Low White Blood Cell Count
- High Zinc
- Low Zinc
Frequently asked questions
Is my data stored?
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.
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.