Pituitary Function Test Calculator

Dynamic endocrine test interpretation.

Medical Disclaimer

This calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about your health. Never disregard professional medical advice or delay seeking it because of results from this tool.

Inputs

Morning Cortisol (µg/dL)

TSH (mIU/L)

Free T4 (ng/dL)

Prolactin (ng/mL)

Peak GH on Stim Test (µg/L)

Tab to move between fields

Results

Cortisol Axis (0–2)

Thyroid Axis (0–2)1

Prolactin Status (0–2)0

GH Axis (0–2)2

Deficient Axes Count0

Panhypopituitarism Flag0

How to Use This Calculator

Enter Morning Cortisol (ug/dL) from an 8 AM draw (or post-stimulation peak).
Input TSH (mIU/L) and Free T4 (ng/dL) to evaluate the thyroid axis.
Enter Prolactin (ng/mL) and Peak GH on Stimulation Test (ug/L).
Review the status of each axis: Cortisol, Thyroid, Prolactin, and GH.
Check Deficient Axes Count and Panhypopituitarism Flag to guide hormone replacement planning.

What each input means

Morning Cortisol (µg/dL): 8 AM fasting cortisol. <3 = likely AI, >18 = intact axis, 3–18 = indeterminate (needs cosyntropin/ITT).
TSH (mIU/L): Thyroid-stimulating hormone. Low/normal TSH with low FT4 suggests central hypothyroidism.
Free T4 (ng/dL): Free thyroxine level. Normal 0.8–1.8 ng/dL.
Prolactin (ng/mL): Serum prolactin. Normal <25. 25–200 = stalk effect/microprolactinoma. >200 = macroprolactinoma.
Peak GH on Stim Test (µg/L): Peak growth hormone level on stimulation test (ITT, GHRH-arginine, glucagon). <3 = GH deficient, 3–5 = borderline.

What each result means

Cortisol Axis (0–2): 0 = Likely adrenal insufficiency (<3), 1 = Indeterminate (3–18), 2 = Intact (>18).
Thyroid Axis (0–2): 0 = Central hypothyroidism, 1 = Normal, 2 = Primary hypothyroidism pattern.
Prolactin Status (0–2): 0 = Normal (≤25), 1 = Mild-moderate elevation (25–200), 2 = Macroprolactinoma range (>200).
GH Axis (0–2): 0 = GH deficient (<3), 1 = Borderline (3–5), 2 = Sufficient (≥5).
Deficient Axes Count: Number of pituitary axes showing deficiency (0–4).
Panhypopituitarism Flag: 1 if ≥3 axes deficient (suggestive of panhypopituitarism), 0 otherwise.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Morning Cortisol (µg/dL) = 12, TSH (mIU/L) = 2, Free T4 (ng/dL) = 1.2, Prolactin (ng/mL) = 10 = 5 input(s) provided
Calculate Cortisol Axis
1 = 1
Calculate Thyroid Axis
1 = 1
Calculate Prolactin Status
0 = 0