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Cortisol Unit Converter
Cortisol is the primary glucocorticoid hormone produced by the adrenal cortex (zona fasciculata) under the regulation of the HPA axis (hypothalamic-pituitary-adrenal axis). It is critical for the body’s response to stress, regulating metabolism (increasing blood glucose), suppressing the immune system, and maintaining blood pressure.[Image of HPA axis regulation]
Cortisol secretion follows a distinct **diurnal rhythm**, peaking in the early morning (8:00 AM) and reaching its lowest point late at night (midnight). Clinically, measuring cortisol at specific times is essential for diagnosing conditions of excess cortisol (Cushing’s syndrome) or deficiency (Addison’s disease). This converter allows precise switching between the SI unit (nmol/L) and the conventional mass unit ($\mu\text{g/dL}$).
SI Units
RecommendedNanomoles per liter (Standard International).
Conventional Units
Clinical Context
Reference Range (8 AM): Normal morning cortisol levels are typically 5 – 25 µg/dL (138 – 690 nmol/L).
Diagnosis of Cushing’s Syndrome often relies on finding elevated cortisol at midnight (loss of nadir). Low levels, especially at 8 AM, suggest Adrenal Insufficiency (Addison’s disease). The conversion factor relies on MW 362.46 g/mol: 1 µg/dL $\approx$ 27.59 nmol/L.
Clinical References
How to Use This Calculator
Follow these steps to get accurate clinical conversions instantly.
Enter Values
Input your laboratory results into the corresponding unit field (e.g., µg/dL). You can use either dot or comma decimals.
Automatic Conversion
The calculator works in real-time. As you type in one field, all other units (like nmol/L) are instantly updated.
Verify Units
Check the SI Units section. nmol/L is the international standard for hormones.
Reset
Use the Clear button to reset all fields before starting a new calculation.
Frequently Asked Questions & Tips
Yes. $\mu\text{g/dL}$ and $\mu\text{g}\%$ are commonly used as equivalent mass units in clinical settings.
Yes, cortisol has a strong diurnal rhythm. Levels drawn at 8 AM vs. midnight cannot be compared directly to each other without specialized interpretation.