ACTH: Function, tests, and ranges Health ConditionsHealth ConditionsAlzheimer's & DementiaAnxietyArthritisAsthma & AllergiesBreast CancerCancerCardiovascular HealthCOVID-19Dermatology & SkincareDiabetesEnvironment & SustainabilityExercise & FitnessEye HealthHeadache & MigraineHealth EquityHIV & AIDSHuman BiologyInflammatory Bowel DiseaseLeukemiaLGBTQIA+Men's HealthMental HealthMultiple Sclerosis (MS)NutritionParkinson's DiseasePsoriasisSexual HealthWomen's HealthDiscoverNewsLatest NewsOriginal SeriesMedical MythsHonest NutritionThrough My EyesNew Normal HealthPodcastsHow to understand chronic painWhat is behind vaccine hesitancy?The amazing story of hepatitis C, from discovery to cureNew directions in dementia researchCan psychedelics rewire a depressed, anxious brain?Why climate change matters for human healthToolsGeneral HealthDrugs A-ZHealth HubsHealth ToolsBMI Calculators and ChartsBlood Pressure Chart: Ranges and GuideBreast Cancer: Self-Examination GuideSleep CalculatorHealth ProductsAffordable Therapy OptionsBlood Pressure MonitorsDiabetic SuppliesFitness TrackersHome GymsGreen Cleaning ProductsHow to Shop for CBDQuizzesRA Myths vs FactsType 2 Diabetes: Managing Blood SugarAnkylosing Spondylitis Pain: Fact or FictionConnectAbout Medical News TodayWho We AreOur Editorial ProcessContent IntegrityConscious LanguageNewslettersSign UpFollow UsMedical News TodayHealth ConditionsDiscoverToolsConnectSubscribe What to know about adrenocorticotropic hormoneMedically reviewed by Kelly Wood, MD — By Mathieu Rees on September 28, 2022Adrenocorticotropic hormone (ACTH) is a hormone that the pituitary gland produces. Its main function is to stimulate the adrenal glands to produce and secrete another hormone called cortisol. Some people refer to cortisol as the body’s stress hormone. Cortisol helps control a wide range of processes throughout the body, including metabolism and immune responses. A doctor can perform an ACTH test to measure how much ACTH a person is producing. This can help diagnose conditions that impact the adrenal and pituitary glands, which can result in unusual levels of cortisol. This article discusses the function of ACTH, the purpose of an ACTH test, and how to interpret test results. ACTH function Share on PinterestCSA Images/Getty ImagesACTH is a tropic hormone. This term refers to types of hormones that function to stimulate other glands within the endocrine system. For example, the anterior pituitary gland produces ACTH, which stimulates the adrenal glands to secrete cortisol. The body uses the hypothalamic-pituitary-adrenal (HPA) axis to control the level of ACTH and cortisol. HPA axis refers to the communication between these regions of the body to regulate hormone levels. When cortisol levels are low, the hypothalamus releases a hormone called corticotrophin-releasing hormone (CRH). This hormone acts on the pituitary gland and stimulates it to release ACTH into the bloodstream. The adrenal gland detects high levels of ACTH, which stimulates it to release cortisol. As cortisol levels begin to rise, the hypothalamus starts to slow the release of CRH, which in turn slows the release of ACTH from the adrenal glands. ACTH levels start to drop as a result, which also causes cortisol levels to decline. Health experts refer to this as a negative feedback loop. This communication helps to regulate hormone levels and stop the body from producing too much or too little. ACTH test purpose The main purpose of an ACTH test is to evaluate the function of ACTH by measuring ACTH levels. This can help doctors diagnose conditions that impact pituitary or adrenal gland function. These conditions can include: Cushing’s disease, where the pituitary gland makes too much ACTHCushing’s syndrome, where the adrenal glands produce too much cortisolAddison’s disease, where the adrenal glands do not make enough cortisolhypopituitarism, a condition where the pituitary does not produce enough hormonesadrenal or pituitary tumors, which can impact hormone production A doctor will typically recommend this test if a person displays symptoms of too much or too little cortisol. They will also usually advise a cortisol level test. Symptoms of too much cortisol can include:weight gainfat accumulation on the back of the neck and shoulderseasily bruisingmuscle weaknessfatigueacneincreased body hairpink or purple stretch marks Symptoms of too little cortisol may include:weight lossfatiguedizzinesscraving saltnausea and vomitingdiarrhea A doctor can also use an ACTH test to help monitor conditions that involve excessive or deficient levels of hormones. Test procedure To perform an ACTH test, medical staff will require a blood sample. This will involve drawing blood through a needle from a vein in the arm. Medical staff will typically disinfect an area on the arm, then place an elastic band further up the arm. This will help to make the veins more prominent. They will then enter a vein with a needle, then use a syringe to draw blood. Both ACTH and cortisol follow a circadian rhythm, meaning levels are usually higher in the morning and lowest during sleep. Additionally, as the blood sample typically requires immediate processing, health experts often perform ACTH tests in the morning, at about 9 a.m. However, a person may have their blood drawn at different points during the day to check for variations in ACTH levels. The sample will then go to a laboratory, which is often on-site in the hospital where staff are collecting the sample. After testing the blood for hormone levels, laboratory staff will send the results to a person’s doctor. The doctor will then interpret the results and discuss them with the individual. Results A person will typically undergo an ACTH test if they have symptoms that suggest an adrenal or pituitary condition, or they have unusual cortisol levels. For an early morning sample, health experts consider 10–60 picograms per milliliter (pg/mL), or 1.3–16.7 picomoles per liter (pmol/L), as a normal range. These values may vary slightly depending on the laboratory. High levels of ACTH may suggest that a person has Cushing’s disease or Addison’s disease. Low levels of ACTH can indicate an adrenal tumor or hypopituitarism. In some cases, the results of the test may not be clear. In these situations, health experts may use synthetic versions of ACTH and cortisol to help with the diagnosis. For example, they may use tetracosactide, a drug version of ACTH, to determine if it tells the adrenal glands to produce cortisol. Similarly, they may use dexamethasone, a drug that acts like cortisol, to see if it stops ACTH production. Some factors may impact results, such as if a person:is under a great deal of stressis menstruating or pregnantis taking certain medications, including other hormones such as steroids or insulindid not sleep well the night before the testhas recently experienced trauma Test risks As the ACTH test requires a blood sample, potential risks are similar to other tests that involve taking blood. This can include:bleedinginfectionbruisingfeeling dizzypain at the injection site Summary Adrenocorticotropic hormone is an important hormone that the pituitary gland secretes. Its main function is regulating another hormone known as cortisol, which has a role in many bodily functions. The level of ACTH in the blood dictates how much cortisol the adrenal glands release. Doctors can measure the levels of these hormones to help determine if the pituitary and adrenal glands are functioning properly and help diagnose health conditions. For example, high ACTH levels may indicate Cushing’s disease or Addison’s disease, while low ACTH can suggest an adrenal tumor or hypopituitarism. Last medically reviewed on September 28, 2022Medical Devices / Diagnostics 8 sourcescollapsedMedical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.ACTH. (2022).https://pathologytestsexplained.org.au/learning/test-index/acthACTH (blood). (n.d.).https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=acth_bloodACTH test. (2020).https://labtestsonline.org.uk/tests/acth-testAdrenocorticotropic hormone. (2020).https://www.yourhormones.info/hormones/adrenocorticotropic-hormone/Adrenocorticotropic hormone (ACTH). (2022).https://www.southtees.nhs.uk/services/pathology/tests/adrenocorticotrophic-hormone-acth/Adrenocorticotropic hormone (ACTH). (2021).https://medlineplus.gov/lab-tests/adrenocorticotropic-hormone-acth/Allen, M. J., et al. (2021). Physiology, adrenocorticotropic hormone (ACTH).https://www.ncbi.nlm.nih.gov/books/NBK500031/Sheng, J. A., et al. (2021). The hypothalamic-pituitary-adrenal axis: Development, programming actions of hormones, and maternal-fetal interactions.https://www.frontiersin.org/articles/10.3389/fnbeh.2020.601939/fullFEEDBACK:Medically reviewed by Kelly Wood, MD — By Mathieu Rees on September 28, 2022 Latest newsWhat sets 'SuperAgers' apart? Their unusually large neuronsOmega-3 may provide a brain boost for people in midlifeSeasonal affective disorder (SAD): How to beat it this fall and winterCDC: Monkeypox in the US 'unlikely to be eliminated in the near future'Why are more women prone to Alzheimer's? New clues arise Related CoverageWhat does a cortisol level test show?Medically reviewed by Stacy Sampson, D.O. A cortisol level test measures the amount of cortisol in the blood. This hormone plays a crucial role in the body. Doctors use cortisol level tests to…READ MOREEndocrine system: How it functions and potential conditionsMedically reviewed by Kelly Wood, MD The endocrine system produces hormones in the body. Learn more about the glands in this system and the types of endocrine disorders and conditions.READ MOREWhat to know about decompression sicknessMedically reviewed by Meredith Goodwin, MD, FAAFP Decompression sickness occurs due to a rapid reduction of pressure following exposure to high pressure. Learn more here.READ MOREBuerger’s disease: What to know Buerger's disease restricts blood flow in the arteries, which can cause tingling sensations, pain, coldness, and color changes. Learn more here. READ MORECommon and rare types of blood cancer The three main types of blood cancer are leukemia, lymphoma, and myeloma, but there are many subtypes and some rarer forms. Learn more here.READ MORE