Renin Aldosterone test

Why am I having this test?

• These blood tests are used to confirm or exclude primary hyperaldosteronism (raised aldosterone levels) – a rare cause of high blood pressure.
• You may have been told that you have high blood pressure (hypertension) or low potassium levels in your blood (hypokalaemia).

Who carries out the blood tests?

A nurse who specialises in endocrinology is responsible for carrying out this test.

Where is the test carried out?

• You will be sent a letter with details of the test and which department you will need to attend.
• If you wish you may bring a companion with you. They may stay with you during the test.

How long will the test take?

The test will take approximately 1 hour to complete.

What do I need to do before the test?

• Your specialist doctor/nurse may stop or change your blood pressure tablets before the test, as they may interfere with the results. You will be advised of this if necessary in your appointment letter.
• If a change of medicine is required, close monitoring of your blood pressure is necessary either at your GP’s surgery or using a home blood pressure monitor. You will need to contact the nurse with your blood pressure readings who will then discuss with you if any changes in your medicine are required.
• You may be asked to have a blood test to check your potassium levels prior to the test, please see your appointment letter for details. It is important that your potassium levels are within the normal range to make sure that the test results are accurate. If your potassium levels are on the low side, the nurse will arrange for you to take the appropriate dose of potassium supplements until the test is complete.
• All other medicine should be taken as usual.
• You may eat and drink as usual before and during the test.

What happens during the test?

• You will meet the nurse who is responsible for the test, on your arrival in the department. The nurse will explain about the test and you will be given the opportunity to ask questions before the start of the test.
• You will need to lie on the bed/couch for approximately 30 minutes with no more than two pillows.
• Some blood samples will then be taken and your blood pressure and pulse will be checked by the nurse.
• You may eat and drink as usual during the test.
• During your appointment you will be given the dexamethasone (steroid) medication and full instructions about the test which you will undertake at home (Overnight Dexamethasone Suppression test).
• If you take any steroid inhalers, creams, nasal sprays or tablets, the nurse will advise you to stop them for 24 hours prior to the test date or longer if required.
• If you take the oral contraceptive pill or HRT (hormone replacement therapy), the nurse may ask you to stop these prior to the test or arrange for an alternative test to be carried out.
• The test is then complete.

Are there any side effects?

If changes are made to your blood pressure medicines prior to the test there is a risk of hypertension (high blood pressure).

What happens after the test?

• On completion of the test you will be safe to resume your normal activities.
• The results will be discussed at your next clinic visit or a letter will be sent to you and your GP.
• The nurse looking after you will arrange a further appointment as required.
• The nurse will advise you when to restart any medicines that were stopped prior to the test.
• If you have had to change any medicines prior to the test, you will be advised when to have your blood pressure checked by the nurse in endocrinology.

If you require more details please contact the Specialist Nurses in Endocrinology:
Tel: 01274 382019 Monday – Friday between 8.00am and 4.00pm except Bank Holidays