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Short synacthen test

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What is the purpose of the test?

The test checks your body’s ability to make a natural steroid hormone or chemical signal called cortisol. Cortisol is produced by the adrenal glands, which are just above the kidneys, in response to instructions from the pituitary gland, which is a small gland beneath the brain.

A problem with either of these glands can result in low cortisol levels. Cortisol has many vital roles in maintaining normal healthy functioning, and is a very important part of the response to ‘stress’ of any kind, including other illnesses.

How long will the test take?

The test will take about 45 minutes in total.

Who will carry out the test?

The test will be carried out by an endocrine specialist nurse or a general nurse.

What will I have to do?

You can eat and drink as normal before this test. If you take steroid hormone therapy (e.g. hydrocortisone or prednisolone) please do NOT take your morning dose before the test. This will enable us to see if you still need this treatment or not.

After the test you should CONTINUE to take your hydrocortisone or prednisolone as usual until the results are available. If you bring your tablets with you, you can take them after the blood samples have all been taken.

Is any drug or medicine used during this test?

You will be given an injection of Synacthen, a natural ‘messenger’ hormone. This is normally produced by the pituitary gland and stimulates the production of cortisol by the adrenal glands.

What will happen during the test?

We will take a sample of your blood sample to measure your cortisol level. We will then inject the Synacthen into a vein or into a muscle such as the buttock. Half an hour after this we will take another blood sample to see how your cortisol level responds to stimulation by Synacthen. After this you can go home.

What are the possible risks or side effects of the test?

This test has no common side-effects or after-effects.

What are the alternatives to the test?

There is no alternative to this test, which is a very safe way to assess your ability to make cortisol.

What will happen after the test?

Your blood samples are sent to the laboratory for analysis. Either the endocrine specialist Nurse or your endocrinologist will discuss the results with you when they are available. If you have been taking hydrocortisone, we will be able to advise you about whether you need long-term hydrocortisone treatment or not.

Who do I contact if I have any questions?

Endocrine Specialist Nurses

Royal Sussex County Hospital
Endocrine specialist nurse 01273 696955 Ext. 64379

Princess Royal Hospital, Haywards Heath

Endocrine specialist nurse 01444 441881 Ext. 65660

If you have any urgent or emergency questions then your GP can advise you or they will contact the hospital on your behalf.

Patient self-help groups and further information:

The UK Addison’s Disease Self Help Group

The Pituitary Foundation

    This information is intended for patients receiving care in Brighton & Hove or Haywards Heath.

    The information in this leaflet is for guidance purposes only and is in no way intended to replace professional clinical advice by a qualified practitioner.

      Publication Date: July 2021

      Review Date: April 2024

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