What happens during an aldosterone test?Aldosterone (ALD) may be measured in blood or urine.During a blood test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.The amount of ALD in your blood can change depending on whether you are standing up or lying down. So you may get tested while you are in each of these positions.For an ALD urine test, your health care provider may ask you to collect all urine during a 24-hour period. Your health care provider or a laboratory professional will give you a container to collect your urine and instructions on how to collect and store your samples. A 24-hour urine sample test generally includes the following steps:Empty your bladder in the morning and flush that urine away. Record the time.For the next 24 hours, save all your urine passed in the container provided.Store your urine container in the refrigerator or a cooler with ice.Return the sample container to your health provider's office or the laboratory as instructed.
