Synacthen test

What is a synacthen test?

A synacthen test (sometimes known as the short synacthen test) checks whether your pituitary gland (a tiny bit inside your brain) and adrenal glands (triangular body parts above your kidneys) are working properly. Cortisol is the stress hormone that is released by the adrenal glands. Cortisol controls your blood pressure and blood sugar levels to help your body in stressful situations such as illness, infection and trauma.

The levels of cortisol in the body are controlled by the pituitary gland and this test is needed to check that everything is working properly.

How does the synacthen test work?

We will give you synacthen, a medication which tells your adrenal glands to make cortisol. We then take a few blood samples at different times to measure your cortisol levels.

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.

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

Unlike surgeries, you can eat during this procedure.

Will it hurt?

Cold spray can be used to numb your child’s skin before we put the cannula in. If your child would prefer to use local anaesthetic cream, you should arrive on Daycare 30 minutes earlier than your appointment time to allow time for this cream to work. You will need to ask the staff on Daycare to apply the cream when you arrive on the ward.

What else happens while I am there?

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

You are also allowed to eat so your can bring your favourite drinks and snacks with you. We will also provide some toast, juice, cereal and snacks.

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 medical team 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.