Hormone and endocrine lab tests, including thyroid markers, sex hormones and cortisol. Explore available tests with reference ranges and context for interpreting results.
Blood, immune, metabolic, hormone, and micronutrient markers are often searched in the context of chronic exhaustion. The surrounding illness logic matters.
What this category can do
Hormone and endocrine lab tests, including thyroid markers, sex hormones and cortisol. Explore available tests with reference ranges and context for interpreting results.
Fatigue
Use the fatigue hub before over-interpreting individual fatigue-related values in isolation.
Open fatigue lab answersPEM
Symptoms that worsen after activity may point to a different logic than simple deficiency thinking.
Open PEM vs normal exhaustionQuestionnaires
Validated assessments help connect lab context to symptom burden and function.
Open questionnairesIf this category is not enough
A category page organizes markers, but many users are actually trying to answer broader questions about fatigue, PEM, pacing, or structured symptom documentation.
Questionnaires
Use validated assessments when a biomarker category alone is too narrow for the underlying question.
PEM
When symptoms worsen after activity, the timing pattern can matter more than a category label.
ME/CFS
Use the illness hub when reduced capacity, fatigue, or multisystem symptoms are part of the larger picture.
Adjacent categories
ACTH is a hormone produced by the pituitary gland that controls cortisol release from the adrenal glands. It is measured to assess pituitary and adrenal function.
Reference: 7.2 - 63.3
Aldosterone is a hormone produced by the adrenal glands that helps control blood pressure and the balance of sodium and potassium in the body.
Reference: Liegend: 30–160 pg/ml, stehend: 70–350 pg/ml (laborabhängig, tageszeitabhängig)
AMH is a hormone produced by the ovaries in women and testes in men. In women, it reflects the ovarian reserve – the quantity of remaining eggs.
Reference: 1 - 10.6
Androstenedione is a steroid hormone produced by the adrenal glands and gonads, serving as a precursor for testosterone and estrogen. It is measured to evaluate adrenal and gonadal function.
Reference: 0.3 - 3.5
Bioavailable testosterone represents the fraction of total testosterone not tightly bound to sex hormone-binding globulin (SHBG) and available for use by the body's cells.
Calcitonin is a hormone made by the thyroid gland that helps regulate calcium balance. It is measured mainly to detect and monitor medullary thyroid cancer.
Reference: < 10 pg/ml (basal, nüchtern) (laborabhängig)
Cortisol is a steroid hormone produced by the adrenal glands that helps regulate metabolism, blood sugar, and the body’s response to stress.
Reference: 5 - 25
Dihydrotestosterone (DHT) is a potent androgen hormone derived from testosterone. It regulates male sexual development, body hair, and prostate function.
Reference: 30 - 85
Dopamine is a neurotransmitter involved in movement, motivation, reward, and mood. Blood measurement is rarely used but may help evaluate certain neuroendocrine tumors.
Reference: Plasma: < 100 pg/ml (laborabhängig, stark methodenabhängig)
Erythropoietin (EPO) is a hormone produced mainly by the kidneys that regulates red blood cell production. It is measured to evaluate anemia, polycythemia, and kidney function.
Reference: 4–25 mU/ml (laborabhängig)
Free T3 (fT3) measures the unbound, biologically active form of triiodothyronine, a thyroid hormone that regulates metabolism and energy production.
Reference: 2 - 4.4
Free T4 (FT4) is the unbound, biologically active form of thyroxine, a hormone produced by the thyroid gland that regulates metabolism, energy, and growth.
Reference: 0.9 - 2.3
Glutamate is a non-essential amino acid and neurotransmitter. Blood levels are measured to evaluate amino acid metabolism and liver health.
Reference: 20–80 µmol/L (laborabhängig)
IGF-I is a hormone that mediates the effects of growth hormone, playing a key role in growth and cell repair.
Reference: 100 - 300
Intact parathyroid hormone (PTH) is a hormone that regulates calcium and phosphate metabolism. This test measures the biologically active form of PTH to assess parathyroid gland function.
Reference: 15.0-65.0
iPTH measures the level of biologically active parathyroid hormone in the blood, which regulates calcium and phosphate balance.
Reference: 15 - 65
Luteinizing hormone (LH) is a pituitary hormone that regulates reproductive function, including ovulation in females and testosterone production in males.
Reference: 1 - 20
Metanephrine is a metabolite of the catecholamine epinephrine (adrenaline). Measuring metanephrine in plasma helps screen for pheochromocytoma and paraganglioma, rare tumors that overproduce catecholamines.
Reference: < 0,5 nmol/l (laborabhängig)
Normetanephrine is a breakdown product of norepinephrine. Measuring it in plasma provides a sensitive and specific way to screen for certain neuroendocrine tumors, particularly pheochromocytoma and paraganglioma.
Reference: < 0.9 nmol/L (laborabhängig)
Procalcitonin (PCT) is a hormone precursor that rises rapidly in response to bacterial infections, helping distinguish them from viral illnesses and guiding sepsis management.
Reference: <0,5 ng/mL (laborabhängig)
Progesterone is a hormone essential for regulating the menstrual cycle, supporting pregnancy, and influencing other body functions. It is measured to assess ovulation, fertility, and certain hormone imbalances.
Reference: 0.1 - 25
Prolactin is a hormone produced by the pituitary gland that regulates lactation and reproductive functions.
Reference: 5 - 25
Renin is an enzyme produced by the kidneys that regulates blood pressure and fluid-electrolyte balance through the renin-angiotensin-aldosterone system (RAAS). Its measurement is primarily used in the investigation of hypertension.
Reference: 2–20 mU/l (im Liegen, laborabhängig)
Reverse T3 is a biologically inactive metabolite of T4. It can change during severe illness or fasting, but it is not a routine test for diagnosing hypothyroidism or guiding thyroid-hormone therapy.
SHBG is a protein that binds to sex hormones like testosterone and estrogen, regulating their availability in the body.
Reference: 18.2 - 135.5
Testosterone is the primary male sex hormone (androgen), produced mainly in the testes in men and in smaller amounts in the ovaries and adrenal glands in women, crucial for sexual development, muscle mass, bone density, and libido.
Reference: 2.5 - 8.4
Thyroxine (T4) is the main hormone produced by the thyroid gland and plays a critical role in regulating metabolism, energy, and overall body function. The T4 blood test is used to evaluate thyroid health and diagnose disorders like hypothyroidism or hyperthyroidism.
Reference: 5 - 12
TSH is a pituitary hormone that regulates thyroid function; it is the primary screening test for thyroid disorders.
Reference: 0.4 - 4
TSH and free T4 are central thyroid tests, with free T3 and thyroid antibodies added for selected questions.
Hormone results can vary with time of day, menstrual cycle, medicines and other factors. They are interpreted together with the reference range, symptoms and, when needed, repeat or additional tests.
