Patient Guide

Hormonal Blood Tests: Complete Guide

Name: Hormonal Blood Tests: Complete Guide for Men and Women
Creator: Suman Konda
Published: 2026-07-05

Hormones control almost every aspect of your health. This guide covers the key hormonal blood tests for thyroid, adrenal, pituitary and reproductive function: and when to order each one.¹

Written by Suman Konda, PharmD, Clinical Pharmacist · Editorial policy · Not medical advice

Last updated: 01 August 2026 · How we check our content

The major hormone systems and their tests

Gland / System	Key Hormones	Primary Blood Tests
Thyroid	T3, T4, Calcitonin	TSH, free T4, free T3, anti-TPO, TRAb
Pituitary	TSH, FSH, LH, ACTH, Prolactin, GH	Prolactin, LH, FSH, ACTH, IGF-1
Adrenal cortex	Cortisol, Aldosterone, DHEA	Morning cortisol, aldosterone:renin ratio, DHEA-S
Adrenal medulla	Adrenaline, Noradrenaline	Plasma metanephrines (for phaeochromocytoma)
Pancreas	Insulin, Glucagon	Fasting insulin, fasting glucose, C-peptide, HbA1c
Gonads (women)	Oestrogen, Progesterone, AMH	Oestradiol, FSH, LH, progesterone, AMH, prolactin
Gonads (men)	Testosterone	Total testosterone, free testosterone, LH, FSH, SHBG
Parathyroid	PTH	PTH, calcium, phosphate, vitamin D

When to test hormones: timing matters

Hormone	Best time to test	Why
Cortisol	8–9am (peak)	Cortisol follows a strong diurnal rhythm
Testosterone	7–10am	Peaks in the morning
Progesterone	Day 21 of a 28-day cycle (7 days after ovulation)	Confirms ovulation
FSH/LH (women)	Day 2–3 of cycle	Basal level; checks ovarian reserve and pituitary
TSH	Any time: fasting not required	Consistent throughout the day
Fasting insulin	After 8–12 hours fasting	Requires fasting
Aldosterone:renin ratio	Morning, after sitting quietly 15 min	Avoid diuretics 4 weeks before

Recognising hormonal imbalance patterns

Fatigue + weight gain + cold intolerance + constipation = check TSH

This is the classic hypothyroid constellation. TSH is always the first test.

Unexplained weight gain + irregular periods + acne + hair growth = check testosterone, LH:FSH ratio, insulin

PCOS (polycystic ovary syndrome) typically shows high LH:FSH ratio, elevated testosterone, and high fasting insulin from insulin resistance.

Fatigue + weight loss + low blood pressure + skin darkening = check morning cortisol + ACTH

These features suggest Addison disease (adrenal insufficiency). A morning cortisol below 5 mcg/dL is strongly suggestive; a short Synacthen test confirms.

High blood pressure + low potassium + fatigue = check aldosterone:renin ratio

This triad suggests primary hyperaldosteronism (Conn syndrome): the most common secondary cause of hypertension. ARR >30 is suspicious; adrenal CT and adrenal vein sampling follow.

Episodic hypertension + palpitations + headache + sweating = check plasma metanephrines

This classic triad suggests phaeochromocytoma: a rare adrenal medulla tumour. Plasma metanephrines are the most sensitive test. Never biopsy an adrenal mass before excluding phaeochromocytoma.

Questions to ask your doctor

Should I test hormones in the morning?
Is my fatigue from thyroid, adrenal or sex hormone imbalance?
Do I need a stimulation test (Synacthen test) for adrenal function?
Could a pituitary problem be causing my hormone imbalance?
Should I see an endocrinologist?

References

Sources cited on this page. PubMed links open the original abstract.

Melmed S, Casanueva FF, Hoffman AR, et al. Diagnosis and treatment of hyperprolactinemia: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96(2):273–288. PMID 21296991 · doi:10.1210/jc.2010-1692

The hypothalamic-pituitary-target-organ axis

Understanding hormonal blood tests requires grasping the three-tier axis that controls hormone production. The hypothalamus releases releasing hormones, which stimulate the pituitary to release stimulating hormones (trophins), which stimulate target organs (thyroid, adrenal, gonads, liver) to produce the final hormones. This feedback system means abnormalities can be diagnosed at any level – and the pattern of which hormone is elevated or suppressed identifies where the problem lies:

High TSH + low T4: Primary hypothyroidism (thyroid gland failing → pituitary working harder to stimulate it)
Low TSH + low T4: Secondary hypothyroidism (pituitary failing – check MRI pituitary)
Low TSH + high T4: Hyperthyroidism (thyroid overproducing → pituitary suppressed)
High LH/FSH + low oestrogen: Primary ovarian failure / menopause (ovaries failing → pituitary working harder)
Low LH/FSH + low oestrogen: Hypogonadotrophic hypogonadism (pituitary or hypothalamic problem – weight loss, exercise excess, prolactinoma)
High ACTH + low cortisol: Primary adrenal insufficiency / Addison's disease
Low ACTH + low cortisol: Secondary adrenal insufficiency (pituitary problem or steroid-induced suppression)
High ACTH + high cortisol: Cushing's disease (pituitary ACTH-secreting tumour)

Common hormonal panels and what they cover

Thyroid panel: TSH (screening), free T4, free T3 (if TSH suppressed to confirm hyperthyroidism), TPO antibodies (autoimmune thyroid disease), thyroglobulin antibodies
Female reproductive hormones: LH, FSH, oestradiol (E2), prolactin (on days 2–5 of cycle for follicular phase assessment), progesterone (day 21 for confirming ovulation), AMH (anti-Müllerian hormone – ovarian reserve)
Male reproductive hormones: Total testosterone (early morning – levels peak at 7–9 am), free testosterone (calculated or measured), LH, FSH (to distinguish primary from secondary hypogonadism), SHBG (sex hormone binding globulin – affects free testosterone availability)
Adrenal panel: Morning cortisol (8–9 am), ACTH, 24-hour urinary free cortisol or overnight dexamethasone suppression test (Cushing's screen), renin and aldosterone (primary hyperaldosteronism screen), DHEAS and 17-OHP (congenital adrenal hyperplasia)
Growth hormone axis: IGF-1 (insulin-like growth factor 1 – the best single marker of GH sufficiency or excess), GH stimulation test (for deficiency), oral glucose tolerance test with GH (for acromegaly – GH should suppress to below 1 mU/L with glucose loading; failure to suppress is diagnostic)