Short synacthen test
What is a short synacthen test?
It is a test to check the amount of cortisol in your body and to check how well your body can produce cortisol.
Cortisol is one of the essential steroid hormones to keep you healthy. You can be unwell if levels of this hormone are too high or too low.
What do I need to do before the test?
Ensure you do not take your steroids for 24 hours prior to your test. Please bring these and any other medication you are taking with you. You should not have the test if you have significant asthma.
How will the test be performed?
You will be made comfortable and seated for the test. You will be introduced to the person performing the test who will explain to you what to expect.
An initial blood sample will be taken to check your baseline level of cortisol. We will then give you an injection to stimulate your own body production of cortisol. A blood sample will be taken 30 minutes later to measure your cortisol levels.
The results will reflect how much cortisol you have and how well your body can respond to the stimulation.
After the test
You will now be able to take your medication as per usual.
Who will get the results?
Your doctor will be informed of the results within three weeks of your test date.
If you have any queries or worries, please do not hesitate to contact the endocrine nurses for further information.
Water deprivation test
What is a water deprivation test?
A water deprivation test is performed to check the regulation of fluid balance and concentration power of your kidneys.
Regulation of the fluid balance is a complex process which involves the pituitary hormone called antidiuretic hormone (ADH), the response of the kidneys to ADH, amount of fluid intake, various salts content of your body, surrounding temperature etc.
This test can only be done under medical supervision as it can potentially cause dehydration, and fluid and salt imbalance.
What do I need to do before the test?
Ensure that you do not take any DDAVP for 24 hours prior to your test.
You are also requested not to eat or drink from the night (midnight) before your test. Please do not overcompensate the previous day by drinking more than usual. (You may like to bring some snacks to eat and drink once you have completely finished your test.) Smoking is also not allowed during your test.
How will the test be performed?
You will be made comfortable for the duration of the test. You will be introduced to the person performing the test, who will explain to you what to expect.
A small needle/canula will be inserted into your arm or back of your hand. This is called a venflon and allows your nurse to obtain blood samples without causing too much discomfort.
This test involves initial measurement of weight, blood and urine concentration (usually at around 09:00).
Your body weight, amount of urine output will be measured hourly.
Blood and urine samples will be collected hourly and sent off to a lab to measure their concentration.
At around 16:00 you will be injected with DDAVP (manufactured medicine similar to natural ADH) and you will then be allowed to take fluid. Urine and blood collection will continue until 20:00.
The aim is to assess the body's response to a lack of fluids and then response after an injection of DDAVP.
After the test
On completion the venflon will be removed. You will be allowed to eat and drink as per usual.
Who will get the results?
Your doctor will be informed of the results.
If you have any queries or worries, please do not hesitate to contact the endocrine nurses for further information.
Oral glucose tolerance test acromegaly
What is a glucose tolerance test?
This test is performed to assess how your body responds regarding your growth hormone release when you are given a sugar drink.
What do I need to do before the test?
You are requested not to eat or drink anything from midnight on the day of your test. If necessary you can have the occasional sip of water. (You may like to bring some snacks to eat and drink once you have completely finished your test.)
How will the test be performed?
You will be made comfortable for the duration of the test. You will be introduced to the person performing the test who will explain to you what to expect.
A small needle/canulla will be inserted into the vein in the back of your hand or arm. This is called a venflon and allows your nurse to obtain blood samples without causing too much discomfort.
An initial blood sample will be taken to check the level of your blood sugar. We will also check the fasting growth hormone level.
You will then be asked to drink a standard amount of glucose, followed by a glass of water within five to ten minutes.
This glucose will raise your blood sugar level. Your body will respond to this glucose and your blood sugar level should be back to normal within two hours after the glucose drink.
Blood samples will be taken every 30 minutes for two hours after the glucose drink, to determine the changes of blood sugar and growth hormone.
The person performing the test will monitor you and will help you if you have concerns or if you feel unwell in anyway.
After the test
On completion your venflon will be removed and you will be able to eat and drink once again. You should have some rest and something to eat after your test.
Who will get the results?
Your doctor will be informed of the results.
If you have any queries or worries, please do not hesitate to contact the endocrine nurses for further information.
Luietinising hormone releasing hormone (LHRH) test
What is an LHRH test?
This test is performed to check how effectively your pituitary gland is working in regulating sex hormone production.
Your pituitary gland is a small gland at the base of the brain, a few inches behind the bridge of the nose, which has a major role in the control of your body's hormone production.
What do I need to do before the test?
You are requested not to eat or drink anything from midnight on the day of the test. (You may like to bring some snacks to eat and drink once you have completely finished your test.)
How will the test be performed?
You will be made comfortable for the duration of the test. You will be introduced to the person performing the test, who will explain to you what to expect.
A small needle/canula will be inserted into a vein in your hand or arm. This is called a venflon and allows your nurse to obtain blood samples without causing too much discomfort.
A blood sample will be taken to check your baseline hormone level of two hormones called LH and FSH which control sex hormone. We will then give you an injection through the canula, which will stimulate your body to produce a rise in both LH and FSH.
Blood samples will be taken at 30 minutes and 60 minutes after the injection to check the hormone level to see how well your body can respond to the stimulation.
After the test
On completion your venflon will be removed and you will be able to eat and drink once again. You should have some rest and something to eat after your test.
Who will get the results?
Your doctor will be informed of the results, usually within three weeks of your test date.
If you have any queries or worries, please do not hesitate to contact the endocrine nurses for further information.
Insulin stress test for growth hormone and cortisol
This test is not advisable for those with significant heart disease or for those who have previously had seizures.
What is the insulin stress test?
This test is performed to check the function of the pituitary gland.
Your pituitary gland is a small gland at the base of the brain, a few inches behind the bridge of the nose, which has major role in the control of your body's hormone production.
What do I need to do before the test?
You are requested not to eat or drink anything from midnight on the day of the test. If you are on any medication, withhold taking hormone replacement therapy, steroid tablets, and thyroxine tablets until the test is complete. Please bring any medication you are taking with you. You may also like to bring some snacks to eat and drink once you have completely finished your test. (It would be advisable to bring a spare shirt, as you will sweat during your test.)
How will the test be performed?
You will be made comfortable for the duration of the test. You will be introduced to the person performing the test, who will explain to you what to expect.
You will then be sent to have an ECG (tracing of the heart).
A small needle/canula will be inserted into a vein in the back of your hand or arm on return from ECG. This is called a venflon and allows your nurse to obtain blood samples without causing too much discomfort.
We will take a blood sample to check your baseline value of cortisol and growth hormone. We will also check your blood sugar level.
We will then give you a calculated amount of insulin, which will reduce your blood sugar to significantly low levels. It is essential to achieve a significantly low blood sugar level so as to stress the brain. Unfortunately, you may feel unwell with shaking, sweating, and feel hungry, tired and sleepy when your blood sugar is at a low level.
You will be observed closely and once your blood sugar is low enough to stimulate your pituitary, we will give you a glucose injection, if necessary, to bring your blood sugar back to normal level.
A bedside check for the blood sugar will be done as necessary during the test until your blood sugar is back to normal and stable.
Blood samples will be taken through the canula in your arm at 30 minute intervals for two to three hours after the injection of insulin to measure your growth hormone and cortisol response to insulin induced low sugar stress. You will be monitored very closely throughout the test.
After the test
On completion your venflon will be removed and you will need to eat prior to going home. You can now take your medication as per usual. You should have some rest and eat after the test.
Who will get the results?
Your doctor will be informed of your results.
If you have any queries or worries, please do not hesitate to contact the endocrine nurses for further information.
Glucagon test for cortisol and growth hormone
What is the glucagon test?
This test is performed to check how effectively your pituitary gland is working in regulating the release of growth hormone and cortisol.
Your pituitary gland is a small gland at the base of the brain, a few inches behind the bridge of the nose, which has major role in the control of your body's hormone production.
What do I need to do before the test?
You are requested not to eat or drink anything from midnight on the day of your test. If you are on any medication, withhold taking hormone replacement therapy, steroid tablets and thyroxine tablets until the test is complete. Please bring with you any medication you are taking. You may also like to bring some snacks to eat and drink once you have completely finished your test.
How will the test be performed?
You will be made comfortable for the duration of the test. You will be introduced to the person performing the test, who will explain to you what to expect.
A small canula /needle will be inserted into a vein in your hand or arm. This is called a venflon and allows your nurse to obtain blood samples without causing too much discomfort.
We will take a blood sample to check your baseline level of two hormones called growth hormone and cortisol as well as glucose. You will then be given an injection of glucagons which will stimulate your body to produce a rise in growth hormone, cortisol and glucose.
Blood samples will be taken at 30-minute intervals for three to four hours after the glucagon injection to check your hormone levels, to measure how well your body can respond to the stimulation.
After the test
On completion your venflon will be removed and you will be able to eat and drink once again. You can now take your medication as per usual. You should have some rest and something to eat after your test.
Who will get the results?
Your doctor will be informed of your results.
If you have any queries or worries, please do not hesitate to contact the endocrine nurses for further information.
Last reviewed: 16 August 2024
