Can this result diagnose a condition on its own?

No. Hormone tests are interpreted together with symptoms, medical history, and other laboratory results.

Which reference range should I use?

Use the reference interval provided by the laboratory that performed your test.

When should I discuss the result with a healthcare professional?

Results that are clearly outside range, persistent, or inconsistent with symptoms should be reviewed by a healthcare professional.

Information about a laboratory test

ACTH: What Does This Blood Test Measure?

Measures ACTH, the pituitary hormone that signals the adrenal glands to produce cortisol.

Test summary

Test name: ACTH
Abbreviations: ACTH
Category: Endocrinology / Pituitary-Adrenal
Panel: Adrenal Function Tests
Specimen: Plasma
Common units: pg/mL, pmol/L

What does the test measure?

Measures ACTH, the pituitary hormone that signals the adrenal glands to produce cortisol.

Why is the test ordered?

Used with cortisol to investigate abnormal cortisol results and evaluate pituitary or adrenal disorders.

Information about a low result

Low ACTH has different meanings depending on cortisol; it may accompany ACTH-independent cortisol excess or pituitary-related adrenal insufficiency.

Information about a high result

High ACTH may occur with low cortisol in primary adrenal insufficiency or with high cortisol in some ACTH-producing conditions.

Reference and clinical context

Use the reference interval printed on your own laboratory report first. Hormone results may vary with the assay, age, sex, pregnancy, menstrual-cycle phase, and sampling time.

Reference range 1

>= 9 – <= 52 pg/mL

Population: Adults
Specimen: Plasma

Example reference interval

Example for an early-morning ACTH sample; laboratory method and specimen handling can affect the result.

Reference ranges may vary by laboratory, method used, age, sex, pregnancy status, and clinical context. The reference range on your own laboratory report takes precedence.

Interpretation notes

ACTH and cortisol should be interpreted together. Sampling time and correct specimen handling are important.

Related specialties

Endocrinology
Internal Medicine
Pediatric Endocrinology

Frequently asked questions

More information about this test

Sources

Cortisol Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2024 · Cortisol testing; circadian timing; adrenal/pituitary context · Verified: Aug 11, 2026
Adrenocorticotropic Hormone (ACTH) — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2023 · ACTH use with cortisol and pituitary/adrenal interpretation · Verified: Aug 11, 2026
ACTH blood test — U.S. National Library of Medicine (MedlinePlus)
Government medical encyclopedia · 2025 · Example early-morning ACTH interval · Verified: Aug 11, 2026