Short Synacthen Test

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Dept of Diabetes and Endocrinology

What is a Short Synacthen® Test (SST) or ACTH stimulation test?

It is a dynamic medical test that assesses how well your adrenal glands respond to adrenocorticotropic hormone (ACTH). This test is the main medical test to diagnose adrenal insufficiency — either primary, secondary or tertiary adrenal insufficiency.

This test is done to assess the function of your adrenal glands. The adrenal glands are situated on top of both kidneys and are responsible for producing cortisol. Cortisol is a hormone which is essential for health and is particularly important in stressful situations. The adrenal glands produce cortisol in response to adrenocorticotrophic hormone (ACTH), a hormone produced by the pituitary gland. During this test you receive an injection of synthetic ACTH to stimulate cortisol release from your adrenal glands. We are then able to assess how much cortisol you are able to produce by taking blood sample.

Why do I need this test?

This test is essential to determine whether there is an adequate level of cortisol production in response to stimulation. Cortisol, a hormone produced by the adrenal glands, plays a crucial role in the body’s response to stress and illness. Additionally, cortisol is involved in the regulation of blood sugar, blood pressure, and the immune system. During periods of illness, the body produces greater amounts of cortisol. Insufficient cortisol production may impair the body’s ability to cope with illness, potentially leading to severe health complications. This test is conducted to investigate suspected adrenal insufficiency.

What are the benefits?

This test will determine whether your adrenal glands can produce an adequate amount of cortisol in response to ACTH. The results will enable the consultant team to decide if you require treatment or, if you are currently undergoing treatment, whether it should be continued. This test will assist in diagnosing adrenal insufficiency, and if diagnosed, we can treat the condition.

My short synacthen test (SST) appointment date and time:

…………………………………………………………………………

Location for my appointment:

Medical day case unit, Level 0, Worcester Royal Hospital, WR5 1DD

Phone: 01905 733462

Different locations:

……………………………………………………………………………

What do I need to do before the test?

The SST is ideally performed between 8:00 am and 9:00 am but can be undertaken at any time of day. If the test is booked after 10:00 am, the doctor may request ACTH and cortisol samples between 8:00 am and 9:00 am at the acute hospital phlebotomy department, if required.

You may need to limit activities 12 to 24 hours before your ACTH stimulation test.

Usually, you should be resting but fasting is not necessary.

Do not need to fast or change diet prior to the test.

If you are taking steroids, you need to adjust the time you take the steroids on the day before and the day of the short Synacthen® test.

If you are taking hydrocortisone tablets or any other steroid (for example, Prednisolone) do not take these tablets on the evening before the test or on the morning of the test.

If you are taking hydrocortisone tablets, your last dose should be at lunch time the day before the test.

If you are on any other types of steroid tablets, your last dose should be more than 24 hours before the short Synacthen® test. For example, if you take prednisolone tablets, your last dose should be 24 hours before the short Synacthen® test. You can take your prednisolone tablet(s) before 7AM on the day before the test.

Do not use any steroid inhalers, nasal spray or creams on the day of the test or for 24 hours before the test.
Bring your steroid medication with you as you will be able to take it immediately after the test is completed.

Inform your consultant team who requested a short Synacthen test if you have received a steroid injection, for example, a knee, shoulder, or nerve block injection….etc.

If you are unwell due to illness, please re-arrange the test or consult with the doctor who advised you to take the test.

If you are pregnant, please inform your endocrine team or consult with the doctor who advised you to take the test.
If you are taking stress-dose or supraphysiological doses of steroids, please re-arrange the test.

If you are taking the oral contraceptive pill (OCP) or hormone replacement therapy (HRT) that contains Oestrogen it should be discontinued for 6 weeks before the test. You will need consider alternative contraception if you wish to avoid pregnancy. You can re-start your OCP or HRT after the SST.

If you are unsure about whether you take a steroid medication or oestrogen, or unsure about when to stop the steroid before the short Synacthen® test please contact our consultant team through the secretary.

My medications that need to hold for the SST:

Name of the medicine …………………………………………………

Last dose of the medication on………………………………………

Name of the medicine …………………………………………………

Last dose of the medication on…………………………………………

Name of the medicine …………………………………………………

Last dose of the medication on…………………………………………

Name of the medicine ………………………………………………….

Last dose of this medication on………………………………………

Name of the medicine …………………………………………………

Last dose of this medication on……………………………………..

Bring your medication with you as you will be able to take it immediately after the test is completed.

How long does the test take?

The test lasts for one hour from the time the nurse gives you the synacthen. You should expect to be in the unit for one and a half to two hours.

How will the test be performed?

You will be introduced to the person performing the test. An explanation will be provided as to what to expect. You should remain seated during the test and will be observed by nursing staff. During this test you will be given an injection of synthetic ACTH (synacthen) into your vein or muscle.

Possible Side Effects of the Short Synacthen Test

As with any new medication there is a small risk of allergic reaction. In extremely rare cases this medication can cause adrenal bleeding. More commonly you may feel warm, light-headed, or nauseous (feeling sick). These feelings should subside quickly.

The basic steps of an ACTH stimulation test include:

A nurse will take a blood sample from a vein in your arm for an initial, baseline level of your cortisol levels and potentially other substances in your blood.
A nurse will give you an injection of synthetic ACTH (tetracosactide) into your muscle or intravenously. The synthetic ACTH acts like your body’s natural ACTH and stimulates your adrenal glands to produce cortisol.
A nurse will take a blood sample from your vein again to measure your cortisol levels after a specified amount of time — usually 30 minutes or 30 and 60 minutes.
Approximate hospital stays for ACTH stimulation test (also known as short Synacthen test (SST)) is one to two hours.

The results will reflect how much cortisol you have and how well your body can respond to the stimulation.

Are there any alternatives?

To assess for hypoadrenalism there are no alternatives to this test.

Complications

There are no long-term complications associated with a Short Synacthen Test.

After care and discharge advice

There are no special precautions you should take following the procedure. You may

return to work/home and drive as you wish. You will now be able to take your medication as usual.

Results

Results will be reviewed by the consultant team. They will either be sent to you by letter or, in some cases, discussed on the phone or with you at your next clinic appointment. We will also send a letter to your GP. This may take up to six weeks or more.

If you have any questions or worries, please do not hesitate to contact the Endocrine Specialist Nurse: Tel: 07563373193 or email

[email protected]

Alexandra Hospital

Endocrine Consultant Secretary on 01527 503890 or 01527 503030 Secretaries Alexandra hospital Redditch: 43890, 44282.

Worcester Royal Hospital or Kidderminster Treatment Centre

Endocrine Consultant Secretary on 01905 733039 or 01905 760671

If your symptoms or condition worsens, or if you are concerned about anything, please call your GP, 111, or 999.

References:

Cleveland Clinic, (2025). ACTH (Cosyntropin) Stimulation Test: What It Is & Results. [online] Available at: https://my.clevelandclinic.org/health/diagnostics/24143-acth-stimulation-test
National Institute for Health and Care Excellence (NICE), (2024). Confirming the diagnosis – Addison’s disease. [online] Clinical Knowledge Summaries (CKS). Available at: https://cks.nice.org.uk/topics/addisons-disease/diagnosis/confirming-the-diagnosis/
King’s College Hospital NHS Foundation Trust (2023) Short synacthen test: Information for patients. [PDF] Available at: https://www.kch.nhs.uk/wp-content/uploads/2023/01/pl-932.1-short-synacthen-test.pdf
East Sussex Healthcare NHS Trust (2022) Short Synacthen Test: Master Patient Information Document. [PDF] Available at: https://www.esht.nhs.uk/wp-content/uploads/2022/03/0963.pdf.

Patient Experience

We know that being admitted to hospital can be a difficult and unsettling time for you and your loved ones. If you have any questions or concerns, please do speak with a member of staff on the ward or in the relevant department who will do their best to answer your questions and reassure you.

Feedback

Feedback is really important and useful to us – it can tell us where we are working well and where improvements can be made. There are lots of ways you can share your experience with us including completing our Friends and Family Test – cards are available and can be posted on all wards, departments and clinics at our hospitals. We value your comments and feedback and thank you for taking the time to share this with us.

Patient Advice and Liaison Service (PALS)

If you have any concerns or questions about your care, we advise you to talk with the nurse in charge or the department manager in the first instance as they are best placed to answer any questions or resolve concerns quickly. If the relevant member of staff is unable to help resolve your concern, you can contact the PALS Team. We offer informal help, advice or support about any aspect of hospital services & experiences.

Our PALS team will liaise with the various departments in our hospitals on your behalf, if you feel unable to do so, to resolve your problems and where appropriate refer to outside help.

If you are still unhappy you can contact the Complaints Department, who can investigate your concerns. You can make a complaint orally, electronically or in writing and we can advise and guide you through the complaints procedure.

How to contact PALS:

Telephone Patient Services: 0300 123 1732 or via email at: [email protected]

Opening times:

The PALS telephone lines are open Monday to Thursday from 8.30am to 4.30pm and Friday: 8.30am to 4.00pm. Please be aware that a voicemail service is in use at busy times, but messages will be returned as quickly as possible.

If you are unable to understand this leaflet, please communicate with a member of staff.

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