Hormonal Blood Tests: Complete Guide for Men and Women

Quick answer

Hormone tests follow the brain's control over each gland: TSH is the first thyroid test, morning cortisol the adrenal check, with sex hormones timed to the day and cycle. The takeaway: timing matters as much as the number, so test at the right hour and cycle day, and read patterns like the LH to FSH ratio rather than single values.

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 (corticotropin) test is the guideline-recommended gold standard to confirm the diagnosis.³

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?

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)², 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)
Pituitary/prolactin: A mildly elevated prolactin is usually repeated, since stress or a non-fasting draw can transiently raise it; drug causes (antipsychotics, some antiemetics and antidepressants) and pregnancy are excluded first, and pituitary MRI is reserved for a significantly and persistently elevated result to look for a prolactinoma.¹

Your next steps for hormone testing

Time the draw correctly
Cortisol between 8 and 9am, testosterone between 7 and 10am, progesterone on day 21 of a 28-day cycle, FSH and LH on days 2–3. TSH is fine at any time. Timing is half the test for hormones.
Think in axes, not single hormones
Read TSH with free T4, LH/FSH with oestrogen or testosterone, ACTH with cortisol. A pituitary signal and its target-gland hormone together locate the problem as gland-side or brain-side.
Read patterns, not single numbers
High LH:FSH ratio with raised testosterone suggests PCOS; low morning cortisol suggests adrenal insufficiency; a mildly raised prolactin is usually just repeated, since stress or a non-fasting draw can raise it.
Ask about confirmation tests
A screening abnormality usually needs a dynamic test to confirm — the short Synacthen test for adrenal insufficiency, the overnight dexamethasone suppression test for suspected Cushing’s. Ask your doctor which one applies.
Know when to ask for a specialist
Persistent pituitary-pattern abnormalities, suspected phaeochromocytoma, or a hormonal picture that doesn’t fit — these are reasons to ask for an endocrinology referral.

Hormone systems and their tests at a glance

The full hormone panel map below covers every major gland. The timing table and pattern-recognition sections in the article show how to use it.

Gland / system	Key hormones	Primary blood tests
Thyroid	T3, T4	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
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 and free testosterone, LH, FSH, SHBG
Parathyroid	PTH	PTH, calcium, phosphate, vitamin D

Practical notes

Timing matters enormously with hormones. Many of them — cortisol, testosterone, TSH, prolactin — follow daily rhythms, so ask the lab what time of day your sample should be drawn and whether it must be fasting. A morning cortisol drawn at 4 pm is, clinically speaking, a different test.

If you are of reproductive age, several hormone tests are cycle-day-specific. Tell the lab the first day of your last period and ask whether the test needs a particular cycle day before you book the appointment.

Bring a full medicine and supplement list — steroids, hormonal contraceptives, thyroid medicine, and biotin all shift results. Ask your doctor which, if any, should be paused and for how long; never stop a prescribed medicine on your own to prepare for a test.

Read hormone panels as patterns, not single numbers — for example, TSH together with free T4, or LH together with FSH. Ask your doctor to walk through the pattern and explain what repeat or follow-up testing it suggests.

In India

Individual hormone tests are typically ₹400–₹1,000 each; panels such as thyroid, PCOS, or fertility profiles are typically ₹2,000–₹7,000, though prices vary by city and lab. Confirm exactly which hormones are included before paying for a panel.

Choose NABL-accredited labs, and for time-sensitive draws confirm that home collection — available in major cities — is scheduled at the right hour. The reference range printed on your own report is the one that counts, since hormone ranges vary with the lab's method and population.

Frequently Asked Questions

What hormone patterns suggest common conditions like PCOS or Addison's disease?

Recognising patterns is how hormone panels are read. PCOS typically shows a high LH:FSH ratio with raised testosterone and high fasting insulin from insulin resistance. A morning cortisol below 5 mcg/dL strongly suggests Addison disease (adrenal insufficiency), confirmed with the short Synacthen test. Resistant hypertension with a high aldosterone:renin ratio points toward Conn syndrome, and episodic headache-sweating-palpitations suggest phaeochromocytoma, best screened with plasma metanephrines.

How does the hypothalamic-pituitary-target-organ axis help interpret hormone results?

The three-tier axis — hypothalamus stimulates pituitary, pituitary stimulates target glands — locates problems by pairing signals. High TSH with low T4 means the thyroid is failing; low TSH with low T4 means the pituitary is the problem. High LH/FSH with low oestrogen indicates ovarian failure, while low LH/FSH with low oestrogen points to a pituitary or hypothalamic cause. The pattern tells you which end of the axis to investigate.

My doctor ordered a morning cortisol — how strict is the timing?

Quite strict. Cortisol peaks shortly after waking, so ‘morning’ usually means within an hour or two of waking, ideally before 9 am. If you miss the window, tell the lab — they will advise whether to still draw the sample or reschedule, because a late sample gets interpreted against the wrong expectation.

I am on birth control pills — will that affect my hormone results?

Yes, hormonal contraceptives change several hormone levels, which is why the lab and your doctor need to know you are taking them. Your doctor can still interpret the results with that context, or may time the test around a pill-free interval — discuss it before the draw, not after.

Do I need to stop biotin before my thyroid test?

Biotin can interfere with many lab immunoassays, including thyroid panels, producing misleading results. Do not stop it on your own — ask your doctor or the lab how long a pause they recommend before the draw, then follow that guidance and tell the phlebotomist.

One hormone is slightly out of range — does that mean I have a condition?

Not by itself. Reference ranges are built so that a small fraction of healthy people fall outside them, and stress, sleep, illness, and timing all move hormones. Your doctor looks at the whole pattern plus your symptoms; a single borderline value usually means watchful follow-up, not a diagnosis.

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
Bhasin S, Brito JP, Cunningham GR, et al. "Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline." J Clin Endocrinol Metab. 2018;103(5):1715–1744. PMID 29562364 · doi:10.1210/jc.2018-00229
Bornstein SR, Allolio B, Arlt W, et al. Diagnosis and Treatment of Primary Adrenal Insufficiency: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2016;101(2):364–389. PMID 26760044 · doi:10.1210/jc.2015-1710

Medical Disclaimer: This page is for general educational purposes only and does not constitute medical advice. Always consult a qualified doctor for diagnosis and treatment.