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Cortisol day curve

Patient information A-Z

Your endocrine doctor has decided that you require several blood tests to find out if you are producing too much cortisol.

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
  • the body to respond to stress

What is a cortisol day curve?

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 may also take all your medication normally and please bring them with you if required.

Females If you are using the oral contraceptive pill or oral HRT you will need to stop them for six weeks prior to your test as they can affect results. If you are using an HRT patch you may continue to do so. If you are stopping the contraceptive pill you must use an alternative contraceptive to avoid pregnancy.

Males If you are using Testim or Testogel please do not apply it on the morning of this test. If you are using Tostran you should apply it as usual.

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 ring 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.

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

Other formats

Help accessing this information in other formats is available. To find out more about the services we provide, please visit our patient information help page (see link below) or telephone 01223 256998.

Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151