Acth Hormone: What Patients Need to Know

ACTH hormone, also called adrenocorticotropic hormone, is made by the pituitary gland and tells the adrenal glands to produce cortisol. When ACTH levels are too high or too low, it can point to a problem affecting the pituitary, adrenal glands, or the body’s stress-hormone balance.

Overview: what ACTH hormone does

ACTH hormone is short for adrenocorticotropic hormone. It is produced by the pituitary gland, a small gland at the base of the brain, and its main job is to signal the adrenal glands to make cortisol. Cortisol supports many essential body functions, including blood pressure control, metabolism, blood sugar balance, inflammation regulation, and the body’s response to physical and emotional stress.

ACTH is part of a tightly regulated system called the hypothalamic-pituitary-adrenal axis, often shortened to the HPA axis. In this system, the brain and adrenal glands continuously communicate to keep cortisol within a healthy range. When cortisol falls, ACTH usually rises to stimulate more production. When cortisol is high, ACTH typically decreases through a feedback process.

For patients, the most important point is that ACTH itself is not usually the direct cause of symptoms. Rather, symptoms tend to come from the hormone imbalance that follows, especially changes in cortisol levels. Because of this, doctors generally interpret ACTH together with cortisol and the clinical picture rather than looking at one isolated number.

Symptoms linked to abnormal ACTH levels

ACTH hormone problems can look different depending on whether ACTH is high, low, or changing in an abnormal pattern. Symptoms are often nonspecific at first, which means they may overlap with many other conditions. A person may feel unusually tired, weak, lightheaded, or notice changes in weight, mood, or skin appearance.

When ACTH is high because the body is trying to raise low cortisol, symptoms may reflect adrenal insufficiency. These can include fatigue, nausea, poor appetite, dizziness, abdominal discomfort, salt craving, and darkening of the skin in some people. If ACTH is high in a condition that also causes excess cortisol, symptoms may instead include weight gain around the trunk, easy bruising, muscle weakness, elevated blood pressure, and high blood sugar.

When ACTH is low, symptoms can occur if cortisol is also low. People may experience weakness, low energy, appetite loss, nausea, or feeling unwell during illness or stress. Some patients have few symptoms, especially if abnormal results are found early during evaluation for another condition.

• Common symptoms: fatigue, weakness, dizziness, nausea
• Possible weight changes: loss of appetite and weight loss, or weight gain with cortisol excess
• Skin changes: darkening with some causes of high ACTH, thinning or bruising with cortisol excess
• Metabolic effects: blood pressure changes, blood sugar changes, and altered mood or sleep

Why ACTH levels become high or low

There are several reasons why ACTH hormone levels may be abnormal. One broad group of causes begins in the adrenal glands. If the adrenal glands cannot produce enough cortisol, the pituitary may respond by making more ACTH. This pattern is often seen in primary adrenal insufficiency, including Addison’s disease.

Another group of causes begins in the pituitary gland. A pituitary disorder can reduce ACTH production, which in turn lowers cortisol. Less commonly, a pituitary tumor can produce too much ACTH, leading to excess cortisol production. This may be considered during evaluation for Cushing’s disease or related conditions of cortisol excess.

Medicines also matter. Long-term use of corticosteroid medications can suppress the body’s natural ACTH production. In some patients, ACTH and cortisol remain low for a period even after the medication is reduced or stopped, which is why steroid changes should always be supervised by a doctor. Severe illness, stress, pregnancy, sleep disruption, and time of day can also influence results, so proper test timing is important.

How doctors test ACTH hormone

An ACTH test is a blood test, but it is usually not ordered alone. Doctors often request ACTH together with a cortisol level, especially a morning cortisol, because hormone levels follow a daily rhythm. ACTH is delicate and must be collected and processed correctly, so careful laboratory handling helps improve accuracy.

If the first results are unclear, additional testing may follow. Depending on the suspected problem, this can include a stimulation test to see whether the adrenal glands respond properly, or a suppression test to see whether cortisol regulation is working normally. Urine or saliva cortisol testing may also be used in selected cases.

Imaging is sometimes needed when blood tests suggest a pituitary or adrenal problem. This may include pituitary MRI or adrenal imaging, chosen according to the pattern of results. If a doctor suspects a structural cause, patients may be referred for MRI scanning or other targeted evaluation.

Because many factors affect hormone testing, one abnormal value does not always mean disease. Doctors consider symptoms, medication history, stress, recent illness, and repeat measurements before making a diagnosis.

What high and low ACTH results may mean

A high ACTH hormone level usually means the pituitary is strongly signaling the adrenal glands. If cortisol is low at the same time, this may suggest that the adrenal glands are not responding as they should. If cortisol is high along with ACTH, doctors may investigate ACTH-dependent causes of cortisol excess, including pituitary overproduction.

A low ACTH level can occur when the pituitary is underactive or when outside steroid medicines suppress natural hormone production. Low ACTH with low cortisol may suggest secondary adrenal insufficiency related to pituitary function. Low ACTH with high cortisol can be seen when cortisol is elevated for reasons that do not depend on pituitary stimulation.

These patterns can sound straightforward, but real-life interpretation may be more complex. Hormone levels naturally change during the day, and some conditions produce intermittent abnormalities. That is why endocrinologists often use a stepwise approach rather than relying on one result alone.

Treatment options and ongoing care

Treatment depends on the underlying cause, not simply on the ACTH number itself. If the issue is adrenal insufficiency, care focuses on replacing the hormones the body is not making adequately and teaching patients how to manage illness, dehydration, or stress safely. If a steroid medication is the cause, a doctor may advise a gradual taper rather than sudden withdrawal.

If testing points to a pituitary or adrenal growth, management may involve specialist follow-up, surgery, medication, or both. In selected situations, doctors may recommend endocrinology evaluation to coordinate diagnosis and long-term management. Some patients also need adrenal surgery or pituitary tumor surgery when a structural cause is confirmed.

Follow-up is important because hormone levels can change over time, and treatment often needs adjustment. Patients may need repeat blood tests, imaging, and review of symptoms such as fatigue, blood pressure changes, blood sugar changes, or medication side effects. Good long-term care usually involves clear instructions on when to seek urgent help, especially for those with adrenal insufficiency.

Near the end of the diagnostic process, some patients benefit from multidisciplinary care. Acibadem International’s specialists and JCI-accredited hospitals diagnose and treat hormone disorders for international patients when coordinated endocrine, imaging, and surgical assessment is needed.

Prevention and self-care

There is no universal way to prevent all ACTH hormone disorders because many arise from autoimmune disease, pituitary conditions, or necessary medical treatment. Still, patients can reduce delays in diagnosis by taking persistent symptoms seriously and attending follow-up appointments when hormone problems are being investigated.

Medication safety is especially important. Corticosteroid tablets, injections, creams, and inhaled medicines can affect the HPA axis, particularly with long-term or high-dose use. Patients should not stop prescribed steroids suddenly unless their doctor specifically advises it, because this can lead to dangerously low cortisol.

Helpful self-care steps include keeping a list of current medicines, reporting new fatigue or dizziness, staying hydrated during illness, and following medical advice about blood tests or repeat monitoring. Patients diagnosed with adrenal insufficiency may also receive individualized sick-day guidance from their care team.

When to seek medical care

Medical advice is appropriate if a person has ongoing fatigue, unexplained weight changes, dizziness, nausea, faintness, skin darkening, easy bruising, or signs of hormone imbalance that do not improve. A doctor can decide whether ACTH and cortisol testing is appropriate and whether symptoms may have another cause.

Prompt care is especially important if symptoms are severe or come on during illness, after surgery, or after changing steroid medication. Urgent evaluation is needed for severe weakness, repeated vomiting, confusion, dehydration, very low blood pressure, or collapse, as these may signal a serious cortisol deficiency state.

Patients already being monitored for pituitary or adrenal disease should contact their doctor if symptoms worsen or if they miss replacement medication. Early review can help prevent complications and keep treatment on the right course.

Frequently asked questions

What is ACTH hormone in simple terms?

ACTH hormone is a messenger made by the pituitary gland in the brain. It tells the adrenal glands, which sit above the kidneys, to make cortisol. Cortisol helps the body manage stress, blood pressure, metabolism, and inflammation.

Is an ACTH test enough to diagnose a hormone disorder?

No. An ACTH test is usually interpreted alongside cortisol levels, symptoms, medical history, and sometimes imaging or follow-up hormone tests. A single result may not give the full answer because ACTH changes through the day and can be affected by illness or medications.

What causes high ACTH hormone levels?

High ACTH can happen when the adrenal glands are not making enough cortisol, so the pituitary tries harder to stimulate them. It can also occur when the pituitary makes too much ACTH. Doctors look at the cortisol level at the same time to understand which pattern is more likely.

What causes low ACTH hormone levels?

Low ACTH may be related to reduced pituitary function or suppression from corticosteroid medicines. In some cases, it appears when cortisol is already high and the body reduces ACTH through normal feedback. A doctor will interpret the result in context rather than on its own.

How should a patient prepare for an ACTH test?

Preparation depends on why the test is being done, but timing is often important because ACTH is usually highest in the morning. The doctor may advise when to have the blood drawn and whether any medicines could affect the result. Patients should always mention steroid use, including inhalers, creams, and injections.

Can stress change ACTH hormone levels?

Yes. Physical stress, illness, poor sleep, and emotional stress can influence ACTH and cortisol levels. That is one reason doctors may repeat testing or use additional tests before confirming a diagnosis.

When is an abnormal ACTH result an emergency?

An abnormal lab result alone is not necessarily an emergency, but symptoms can be. Severe vomiting, collapse, confusion, dehydration, or very low blood pressure need urgent medical assessment, especially in someone with suspected or known adrenal insufficiency. Patients should seek immediate care if these warning signs appear.

References

• National Institute of Diabetes and Digestive and Kidney Diseases
• Endocrine Society
• MedlinePlus
• Merck Manual Consumer Version

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.