Corticotropin releasing hormone (CRH) test

What is a CRH?

Corticotropin releasing hormone (CRH) tells the brain to release the adrenocorticotropic hormone (ACTH). ACTH tells the kidneys to make cortisol which is your body’s stress hormone.

Your doctor thinks you are making too much of this stress hormone (cortisol) so we are doing a test to find this out. Making too much cortisol can be a sign of Cushing’s syndrome.

This test can also be used to test the pituitary gland, which is a bit of your kidney which tells your body to when make the stress hormone.

How does the CRH test work?

We will give you medication to tell your pituitary gland to either stop or start making cortisol. We do this by giving your body a synthetic version of CRH through a vein. We then take a few blood samples at different time to measure levels of ACTH and cortisol.

The easiest way to give the medication and take the blood samples is by putting a plastic tube called a ‘cannula’ into a vein. This usually goes in the back of the hand or arm. A local anaesthetic cream or cold spray will be used to help stop any pain and discomfort.

Please arrive 30 minutes earlier than your appointment time to allow for this cream to work.

The test can be done as a day case the test usually takes around 2 hours.

Unlike surgeries, you can eat during this procedure.

What else happens while I’m there?

Once the cannula is in, you can play with toys, read books and watch TV.

You are also allowed to eat so your can bring your favourite drinks and snacks with you. Some toast, juice, cereal and snacks will be provided too.

What about my medications?

If you have any prescribed medications, they should be taken as normal before you come in. Please double check this with your doctor if you are not sure.

What happens after my test?

You will be discharged once you have fully recovered from the test and feeling well.

When will my results come back?

The results take around 1 month to be analysed. Your consultant might write to you with the results or want to talk about them with you at your next appointment.

What happens if I cannot make my appointment?

Please make every effort to attend the appointment. If the date or time you have been given is not convenient or your child is unwell, please contact the Endocrine nurse on 0114 226 7815.