This test is usually done at home. You must collect all the urine you produce in a 24-hour period.

• When you first get up in the morning, urinate into the toilet. Don't save this urine. This marks the start of your 24-hour period.
• For the next 24 hours, collect all your urine. Your doctor or lab will give you a large container to store it in. Urinate into a separate small, clean container. Then pour the urine into the large container. Don't touch the inside of the containers with your fingers.
• Keep the large container in the refrigerator.
• Empty your bladder for the last time at or just before the end of the 24-hour period. Add this urine to the large container, and write down the time.
• Do not get toilet paper, pubic hair, stool (feces), menstrual blood, or anything else in your urine sample.

This test usually doesn't cause any pain or discomfort.

There are no known risks from having this test.

Normal

Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.

High values

High aldosterone levels can be caused by:

• A tumour in the adrenal glands (Conn's syndrome).
• Heart failure.
• Kidney disease.
• Liver disease.
• A condition during pregnancy that causes high blood pressure (preeclampsia).
• Some medicines that are used to treat high blood pressure.

Low values

Low aldosterone levels can be caused by:

• Addison's disease.
• Kidney disease, such as the types of kidney disease seen in people who also have diabetes.
• Heparin treatment. Heparin is a medicine that helps prevent blood clots. It is given as a shot.