Endocrinology Tests Directory
A practical guide to hormone testing, thyroid disorders, diabetes, fertility, pituitary and adrenal function, and calcium–bone metabolism. Explore test principles, specimen requirements and clinical interpretation considerations.
Browse Hormone Tests
Loading...Thyroid-Stimulating Hormone (TSH)
Common first-line test for assessment of thyroid function.
Clinical interpretation
Interpret with free T4, symptoms, medications and clinical context. Pregnancy-specific intervals may be required. Biotin and assay interference can affect some methods.
Free Thyroxine (FT4)
Measures the unbound fraction of circulating thyroxine.
Clinical interpretation
Used with TSH to evaluate thyroid dysfunction. Abnormal pituitary function, pregnancy, binding-protein changes and assay interference can complicate interpretation.
Free Triiodothyronine (FT3)
Measures free circulating T3, the more biologically active thyroid hormone.
Clinical interpretation
May be useful when hyperthyroidism is suspected or T3 thyrotoxicosis is considered. FT3 is generally less useful than TSH and FT4 in routine assessment of hypothyroidism.
Anti-Thyroid Peroxidase Antibody (Anti-TPO)
Detects antibodies associated with autoimmune thyroid disease.
Clinical interpretation
Supports autoimmune thyroiditis in the appropriate setting. Positivity can occur in people with normal thyroid function and does not independently determine treatment.
Anti-Thyroglobulin Antibody (Anti-Tg)
Measures antibodies directed against thyroglobulin.
Clinical interpretation
May support evaluation of autoimmune thyroid disease. Anti-Tg antibodies can also interfere with thyroglobulin measurement during follow-up of differentiated thyroid cancer.
TSH Receptor Antibodies (TRAb)
Assesses antibodies directed against the TSH receptor.
Clinical interpretation
Useful in evaluation of Graves' disease and selected pregnancy-related risk assessments. The assay may detect stimulating, blocking or combined antibody activity depending on the method.
Total T4 and Total T3
Measure total circulating thyroid hormone, including protein-bound fractions.
Clinical interpretation
Results are affected by thyroid hormone-binding proteins, pregnancy, estrogen and some medications. Free hormone testing and TSH may help clarify discordant results.
Fasting Plasma Glucose (FPG)
Measures glucose after the laboratory-specified fasting period.
Clinical interpretation
Used in diabetes screening and diagnosis. Diagnostic thresholds and confirmation requirements should follow current clinical guidance. Delayed sample processing can lower glucose.
Postprandial Blood Glucose
Measures glucose at a specified interval after a meal.
Clinical interpretation
Meal composition and timing affect the result. It is not interchangeable with a standardized oral glucose tolerance test.
HbA1c
Reflects average glycemia over approximately the preceding 2–3 months.
Clinical interpretation
Can be misleading with altered red-cell lifespan, recent blood loss or transfusion, some hemoglobin variants, and certain anemias. Use a validated method and clinical context.
Oral Glucose Tolerance Test (OGTT)
Measures glucose response to a standardized glucose load.
Clinical interpretation
Used in selected diagnostic situations, including gestational diabetes screening protocols. Preparation, fasting, glucose load and sample timing must follow the applicable protocol.
Fasting Insulin
Measures circulating insulin under fasting conditions.
Clinical interpretation
May be used in selected investigations of glucose metabolism or hypoglycemia. It is not, by itself, a definitive diagnostic test for insulin resistance.
C-Peptide
Helps assess endogenous insulin secretion.
Clinical interpretation
Useful in selected cases to help distinguish endogenous insulin secretion from injected insulin. Interpret with simultaneous glucose, kidney function and medication history.
Proinsulin
Measures the precursor of insulin.
Clinical interpretation
May contribute to specialist investigation of endogenous hyperinsulinemic hypoglycemia. Results should be interpreted with concurrent glucose, insulin, C-peptide and clinical findings.
Prolactin
Evaluates elevated prolactin and selected reproductive or pituitary disorders.
Clinical interpretation
Stress, pregnancy, medications, hypothyroidism and macroprolactin can influence results. Mild elevations may need repeat testing under appropriate conditions.
Growth Hormone (GH)
Measures circulating growth hormone.
Clinical interpretation
GH secretion is pulsatile, so a random result is often difficult to interpret. Dynamic suppression or stimulation tests may be needed for suspected acromegaly or GH deficiency.
IGF-1
Measures insulin-like growth factor 1, a marker related to GH activity.
Clinical interpretation
Interpret using age-appropriate reference intervals. Nutrition, liver function, pregnancy and other illnesses may affect IGF-1; confirmatory testing may be needed.
ACTH
Measures adrenocorticotropic hormone involved in adrenal cortisol regulation.
Specimen considerations
ACTH is sensitive to collection and handling conditions. Use the laboratory's specified collection tube, transport temperature and processing instructions.
FSH and LH
Gonadotropins involved in reproductive function and gonadal hormone regulation.
Clinical interpretation
Interpret with age, sex, menstrual-cycle timing, pregnancy status and relevant medications. They can help investigate infertility, amenorrhea and gonadal dysfunction.
Water Deprivation / Copeptin Testing
Specialist investigations of selected disorders of water balance.
Clinical interpretation
Investigation of diabetes insipidus and related conditions requires supervised protocols and careful monitoring. These tests should not be attempted without appropriate medical oversight.
Serum Cortisol
Measures cortisol, an adrenal hormone with a strong daily rhythm.
Clinical interpretation
Collection time, sleep schedule, stress, estrogen and corticosteroid medication can affect results. A single random cortisol is not sufficient for every adrenal disorder.
ACTH Stimulation Test
Assesses adrenal cortisol response to synthetic ACTH.
Clinical interpretation
Used in evaluation of suspected adrenal insufficiency. Sampling times, cortisol assay and decision thresholds must follow a validated local protocol.
Overnight Dexamethasone Suppression Test
Assesses suppression of cortisol after dexamethasone administration.
Clinical interpretation
Used in selected evaluations for cortisol excess. Medication interactions, adherence, estrogen exposure and other factors can affect results.
Late-Night Salivary Cortisol
Assesses cortisol at a time when concentrations are normally low.
Clinical interpretation
Used in selected screening pathways for cortisol excess. Collection time, sleep pattern, contamination and assay-specific cutoffs are important.
24-Hour Urinary Free Cortisol
Measures unbound cortisol excreted in a timed urine collection.
Clinical interpretation
Collection completeness, urine volume, renal function and assay method affect interpretation. Multiple measurements may be required in appropriate diagnostic pathways.
Plasma Free Metanephrines
Measures metabolites used in investigation of catecholamine-producing tumours.
Clinical interpretation
Collection conditions, posture, stress and medicines may affect results. Follow laboratory-specific preparation and sampling instructions.
Aldosterone and Renin
Assesses the renin–angiotensin–aldosterone system.
Clinical interpretation
Used in selected evaluations for primary aldosteronism and other mineralocorticoid disorders. Potassium, posture, sodium intake and medications can substantially alter results.
Plasma Renin Activity / Direct Renin
Measures renin activity or renin concentration.
Clinical interpretation
Interpret together with aldosterone and collection conditions. Renin activity and direct renin concentration are different measurements and are not directly interchangeable.
Total Testosterone
Measures total circulating testosterone.
Clinical interpretation
For many adult male evaluations, morning collection and confirmation of low results are recommended. Age, SHBG, medications and clinical context matter.
Free Testosterone / SHBG
Assesses testosterone binding and estimated or measured free hormone.
Clinical interpretation
SHBG affects the relationship between total and free testosterone. Direct free-testosterone immunoassays may be unreliable; the method should be appropriate to the clinical question.
Estradiol (E2)
Measures a major estrogen involved in reproductive and other physiological functions.
Clinical interpretation
Interpret with sex, age, menstrual-cycle stage, pregnancy status and medication use. Low concentrations may require a more sensitive method.
Progesterone
Assesses progesterone production in selected reproductive evaluations.
Clinical interpretation
Timing relative to ovulation is essential. A single measurement may support assessment of recent ovulation but cannot reliably assess every aspect of luteal function.
Anti-MĂĽllerian Hormone (AMH)
Measures a marker associated with ovarian follicular reserve or testicular Sertoli-cell function, depending on context.
Clinical interpretation
Used in selected fertility and ovarian-reserve assessments. AMH alone does not reliably predict natural conception or guarantee an individual fertility outcome.
Beta-hCG
Measures human chorionic gonadotropin for pregnancy assessment and selected tumour-related investigations.
Clinical interpretation
Serial serum measurements and ultrasound may be used in selected clinical settings. A single value does not establish pregnancy location or viability.
DHEA-S
Measures dehydroepiandrosterone sulfate, an androgen predominantly associated with adrenal production.
Clinical interpretation
May help investigate androgen excess. Interpretation depends on age, sex, clinical features and other androgen measurements.
Parathyroid Hormone (PTH)
Measures the hormone regulating calcium and phosphate homeostasis.
Clinical interpretation
Interpret with calcium, phosphate, vitamin D and kidney function. Sample handling requirements and assay generation can influence results.
25-Hydroxy Vitamin D
Commonly used laboratory marker of vitamin D status.
Clinical interpretation
Interpret using the laboratory's reference guidance and clinical context. It is distinct from 1,25-dihydroxy vitamin D, which is used for selected indications.
1,25-Dihydroxy Vitamin D
Measures the active form of vitamin D.
Clinical interpretation
Not usually the preferred test for routine vitamin D status. It may be requested for selected calcium, kidney or granulomatous disorders.
Calcitonin
Measures a hormone produced by thyroid C cells.
Clinical interpretation
May be used in selected evaluation or follow-up of medullary thyroid carcinoma. Renal function, smoking and assay factors can affect results.
Osteocalcin / P1NP / CTX
Selected markers of bone formation and resorption.
Clinical interpretation
May be used in selected bone-metabolism or treatment-monitoring contexts. Fasting status, collection time, kidney function and sample handling can affect certain markers.
Thyroglobulin
A protein used in selected follow-up settings for differentiated thyroid cancer.
Clinical interpretation
Anti-thyroglobulin antibodies may interfere with results. Interpretation depends on treatment history, residual thyroid tissue, assay consistency and clinical findings.
Plasma or Urinary Metanephrines
Biochemical investigation for suspected catecholamine-producing tumours.
Clinical interpretation
Selection of plasma versus urine testing and patient preparation should follow the applicable clinical pathway and laboratory protocol.
Gastrin
Measures a hormone involved in gastric acid secretion.
Clinical interpretation
May be used in selected evaluations for hypergastrinemic disorders. Proton-pump inhibitors, gastric acidity and specimen requirements can substantially affect interpretation.
17-Hydroxyprogesterone
Measures a steroid precursor used in selected adrenal and reproductive evaluations.
Clinical interpretation
May be used when investigating congenital adrenal hyperplasia and selected causes of androgen excess. Age, collection time, menstrual-cycle phase and method affect interpretation.
Androstenedione
Measures an androgen precursor produced by adrenal glands and gonads.
Clinical interpretation
May contribute to investigation of androgen excess. Interpret with testosterone, DHEA-S, age, sex and relevant reproductive context.
Chromogranin A
A marker sometimes used in selected neuroendocrine tumour evaluations.
Clinical interpretation
Not a stand-alone diagnostic test. Proton-pump inhibitors, kidney dysfunction and other conditions can cause elevations; use only where clinically appropriate.
0 Comments