The ACTH, Plasma test contains 1 test with 1 biomarker.
Description: ACTH is a blood test that measures the amount of the adrenocorticotropic hormone in the body’s system. The results can be used to help diagnose or monitor a hormone imbalance or a specific condition or disease related to the pituitary gland.
Also Known As: Adrenocorticotropic Hormone Test, Corticotropin Test, Cosyntropin Test
Collection Method: Blood Draw
Specimen Type: Plasma
Test Preparation: Collect specimen between 7 a.m. and 10 a.m. If drawn at any other time, the reference ranges do not apply
When is an ACTH test ordered?
When a cortisol test reveals aberrant results or when someone has indications or symptoms of excess or inadequate cortisol, an ACTH test may be recommended.
Cortisol excess can induce the following symptoms:
- Fat between the shoulders
- Red, rounded face
- Skin that is fragile and thin
- Purple lines on the abdomen
- Muscle loss
- Skin problems
- Excessive body hair
High blood pressure, low potassium, high bicarbonate, high glucose levels, and occasionally diabetes are all common with these symptoms.
People with low cortisol levels may have symptoms such as:
- Muscle wasting
- Loss of weight
- Skin pigmentation increases, even in places not exposed to the sun
- Appetite loss
- Nausea, vomiting, and diarrhea
- Cravings for salt
Low blood pressure, low blood glucose, low sodium, high potassium, and high calcium are frequently found in conjunction with these symptoms.
Several of the following symptoms are commonly associated with hypopituitarism:
- Appetite loss
- Menstrual cycle irregularity
- Sexual organ dysfunction
- Reduced sexual desire
- Urination during the night
- Unprecedented weight loss
- Hot flashes
- sensitivity to cold
When a pituitary tumor causes symptoms, the affected person may also experience symptoms related to the compression of adjacent cells and nerves. The tumor, for example, can modify the pattern of headaches. It can also impair the nerves that control vision, creating symptoms like "tunnel vision," localized visual loss, or "double vision."
What does an ACTH blood test check for?
Adrenocorticotropic hormone is a hormone that promotes cortisol production. Cortisol is a steroid hormone produced by the adrenal glands that regulates glucose, protein, and lipid metabolism, suppresses the immune system's reaction, and aids in blood pressure regulation. This test determines how much ACTH is present in the blood.
The pituitary gland is responsible for producing ACTH. The pituitary gland is a network of glands that work together to create hormones that operate on organs, tissues, and other glands to govern systems throughout the body. It is located below the brain in the center of the head.
ACTH levels rise when cortisol levels are low and fall when cortisol levels are high. The hypothalamus produces corticotropin-releasing hormone in response to a drop in blood cortisol levels. This causes the pituitary gland to produce ACTH, which in turn stimulates the adrenal glands, which are small organs at the top of each kidney, to produce cortisol. The brain, pituitary, and adrenal glands must all be operating properly in order to produce enough levels of cortisol.
Conditions affecting the hypothalamus, pituitary, or adrenal glands can disrupt the regulation of ACTH and cortisol production, causing the glands to generate more or less of the hormones. This can result in signs and symptoms linked with cortisol excess or insufficiency. Cushing disease, Addison disease, and hypopituitarism are all conditions that impact ACTH. Some tumors outside of the pituitary, such as those in the lungs, can also produce ACTH, which raises cortisol levels.
Lab tests often ordered with an ACTH test:
- Cortrosyn Stimulation test
- Dexamethasone Suppression Test
Conditions where an ACTH test is recommended:
- Addison Disease
- Adrenal Insufficiency
- Cushing Syndrome
- Endocrine Syndromes
How does my health care provider use an ACTH test?
ACTH blood tests are used to detect, diagnose, and monitor problems related with excessive or deficient cortisol in the body, usually in conjunction with cortisol tests. These circumstances include:
- Cushing disease is characterized by high cortisol levels caused by an ACTH-producing tumor in the pituitary gland.
- Cushing syndrome refers to the symptoms and signs of high cortisol levels; it can be caused by an adrenal tumor, adrenal hyperplasia, steroid use, or an ACTH-producing tumor outside the pituitary, such as in the lungs.
- Cortisol production is reduced in Addison disease due to adrenal gland injury.
- Secondary adrenal insufficiency: pituitary dysfunction causes decreased cortisol production.
- Hypopituitarism is pituitary dysfunction or injury that causes the pituitary to produce less hormones, notably ACTH.
Because the level of ACTH generally varies in the opposite direction of the level of cortisol, measuring both can assist distinguish between some of these diseases.
If abnormal levels are found, a healthcare professional will do additional testing to confirm the results and discover the cause.
What do my ACTH test results mean?
The interpretation of the results can be difficult in many circumstances. ACTH and cortisol levels fluctuate throughout the day. ACTH levels are normally highest in the morning and lowest at night. It will increase cortisol production, which will follow the same daily rhythm as ACTH but rise later in the day and fall later in the evening. This diurnal rhythm is frequently disrupted by conditions that influence ACTH and cortisol synthesis.
ACTH and cortisol patterns associated with various illnesses of the adrenal and pituitary glands.
An adrenal tumor, steroid treatment, or hypopituitarism can all cause a reduction in ACTH.
Cushing disease and ectopic ACTH cannot be reliably distinguished from cortisol and ACTH measurements alone. Other tests are also performed to aid healthcare providers in determining this distinction. When some medications are given to promote or repress hormone synthesis, testing the change in cortisol levels might assist the healthcare practitioner establish the correct diagnosis.
We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.