Cortisol day curve

Your endocrine doctor has decided that you require a series of blood tests either to find out if you are producing too much cortisol or to determine if you are taking the correct dose of hydrocortisone replacement.

What is cortisol?

Cortisol is one of the hormones produced by the adrenal glands and is vital for health. It has many functions which include helping:

• to regulate blood pressure
• to regulate the immune system
• to balance the effect of insulin in regulating the blood sugar level
• your body to respond to stress

What is a cortisol day curve?

A cortisol day curve is a test which looks at your cortisol levels throughout the day.

Do I need to prepare for this test?

You do not need to fast for this test. You should take all your medication normally and please bring them with you if required.

For females who are using the combined oral contraceptive pill (i.e. a pill that contains both oestrogen and progesterone) or oral HRT containing oestrogen you will need to stop them for six weeks prior to your test as these preparations can affect the laboratory results. If you are using an HRT patch or other form of transdermal oestrogen (e.g. gel) you may continue to do so. If you are stopping the combined oral contraceptive pill you must use an alternative contraceptive to avoid pregnancy.

Please ask before stopping any medications if you are unsure.

How long will this test take?

This test will require you to stay in the hospital for around six to eight hours. You should come to the Endocrine Investigation Unit by 09:00.

You do not have to stay in the unit the whole day but you may do so if you wish. Please bring something to eat as we do not have catering facilities available. We do provide tea and coffee. You may also like to bring something to occupy yourself during your stay.

You should be able to undertake normal activities after the test is finished and it should not interfere with your ability to drive home.

What will happen during the test?

You will need to arrive at the Endocrine Investigation Unit by 09:00. A fine plastic tube called a cannula will be inserted into a vein in your arm, to allow us to take blood samples at regular intervals either hourly or two hourly.

Will I experience any side effects?

There are no side effects of this test but you may experience some discomfort from the cannula.

When will I get my results?

Results cannot be given out over the telephone and will be discussed at your next clinic appointment.

General information

Discounted parking is available for patients attending clinic appointments over three hour’s duration. Please present your appointment letter to receive this.

Food and drink -there is a coffee shop in the treatment centre atrium and further food and drink facilities in the main hospital concourse.

If you need any help or any advice please leave a voicemail with the endocrine nurses on 01223 217848

We are situated in the Wolfson Diabetes and Endocrine Clinic on level 2 (ground level) in the Addenbrooke’s Treatment Centre (ATC) on the left side of the lifts. Please report to the clinic reception and they will show you round to the endocrine unit.