About

Interpreting endocrine laboratory results requires navigating a complex landscape of varying units, demographic-specific reference intervals, and physiological states. Standard laboratory reports often provide a generic reference range that may not account for specific conditions such as pregnancy trimesters or menstrual cycle phases. Misinterpretation of these values can lead to unnecessary anxiety or missed diagnoses.

This tool addresses the ambiguity of hormonal analysis by contextualizing user data against clinically accepted standards. It handles critical unit conversions, such as transforming Progesterone from ng/mL to nmol/L, ensuring values are compared against the correct metric. The system segments data by biological sex, age groups, and specific reproductive stages including Follicular, Ovulation, and Luteal phases, as well as distinct pregnancy trimesters where hormones like Free T4 and HCG fluctuate significantly.

Formulas

Accurate interpretation relies on dimensional analysis to align user input with reference database units. The conversion generally follows the linear relationship:

Value_target = Value_source × Factor

For molar conversions, the factor is derived from the molecular weight (MW) of the substance. For example, converting Progesterone from mass concentration to molar concentration uses:

ngmL × 3.18 ≈ nmolL

Where the factor 3.18 represents 1000 ÷ MW_prog (approx 314.47 g/mol).

Reference Data

Hormone	Standard Unit	Alt Unit	Conv. Factor	Context	Ref Range (Example)
Thyroid Stimulating Hormone (TSH)	mIU/L	uIU/mL	1.0	Adult	0.40 - 4.50
Free T4 (Thyroxine)	ng/dL	pmol/L	12.87	Pregnancy (1st Tri)	0.70 - 1.20
Total Testosterone	ng/dL	nmol/L	0.0347	Male (Adult)	264 - 916
Estradiol (E2)	pg/mL	pmol/L	3.67	Female (Ovulation)	64 - 357
Progesterone	ng/mL	nmol/L	3.18	Female (Luteal)	1.8 - 23.9
Cortisol (Serum)	mcg/dL	nmol/L	27.59	AM (8:00)	6.2 - 19.4
Prolactin	ng/mL	mIU/L	21.2	Female (Non-preg)	4.8 - 23.3
Vitamin D (25-OH)	ng/mL	nmol/L	2.496	General Health	30 - 100
Ferritin	ng/mL	ug/L	1.0	Female	15 - 150
FSH	mIU/mL	IU/L	1.0	Menopause	25.8 - 134.8

Frequently Asked Questions

Reference intervals are established by laboratories using their specific assay equipment and local population data. One lab might define the upper limit of TSH as 4.5 mIU/L, while another sets it at 4.0 mIU/L. Always prioritize the range printed on your specific lab report over generic online tools if they differ significantly.

Many hormones follow a circadian rhythm. Cortisol, for example, peaks in the early morning (around 8 AM) and drops significantly by evening. Testosterone is also highest in the morning. Testing at the wrong time can result in false low or high readings relative to standard reference ranges.

Estradiol, LH, FSH, and Progesterone fluctuate dramatically during the menstrual cycle. A "normal" Progesterone level for the Follicular phase (pre-ovulation) would be considered pathologically low for the Luteal phase (post-ovulation). Interpreting results without phase context renders the data medically useless.

Yes. High doses of Biotin (Vitamin B7) can interfere with immunoassay technology used for TSH and T4 tests, often causing falsely low TSH and falsely high T4 results. This mimics hyperthyroidism. It is generally recommended to stop biotin supplements 48-72 hours before blood draws.

Yes, drastically. During pregnancy, Total T4 increases due to higher thyroxine-binding globulin, while TSH reference limits are often lower (e.g., 0.1-2.5 mIU/L in the first trimester). Using non-pregnant ranges for a pregnant individual can lead to incorrect diagnoses of hypothyroidism or hyperthyroidism.