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Hormone Testing

How are hormone tests preformed?

Saliva Tests

Saliva testing is also commonly used to evaluate hormone levels, although the majority of information available on hormones has been done with blood or urine measurements. Radioimmunoassay, the same technique used for blood tests, is often used to analyze hormones from a collection of saliva.

Similar to blood tests, each saliva sample represents only a snapshot. Some commercial labs offer saliva test kits for collecting several samples throughout a day or throughout a month, so that they have more data to evaluate. Saliva samples are noninvasive and easy to collect with such frequency.

Only “free” hormones are filtered from the blood into the saliva and, therefore, these tests are a very accurate measure of the hormones that are biologically active or available to other tissues.

Urine Tests

The oldest and perhaps easiest method of measuring hormones is urine testing. It is relatively easy to measure hormones in urine because larger amounts appear in urine than in blood or saliva.

Urine testing requires that the patient collect every drop of urine for 24 hours. The test is not accurate if only some of the urine is collected over the 24-hour period, or if some of the urine is discarded. In addition, if kidney function is impaired, test results may not be reliable. For this reason, a kidney function test is often requested in conjunction with a urine-based hormone test.

Identification of hormones in urine is usually achieved using a technique called mass spectroscopy, which precisely identifies each hormone found. Although this method does not identify the high and low levels that can occur within normal daily fluctuations, it is still a good measure of how much of a specific hormone is available on that particular day.

Some urine tests also track specific hormones and their metabolites, which helps assess if hormone supplementation has had an impact on more than one hormone.

Blood Tests

As testing techniques improved and it became possible to identify smaller quantities of hormones, tests and hormone measurements using blood samples became more readily available.

In one method of blood testing, one or more vials of a patient’s blood are collected during a lab appointment and the separated serum is measured for hormone levels. Serum measurements do not account for many hormones which are bound to carrier proteins.

Critics of this method claim that the invasive procedure, in and of itself, can alter the circulating hormones. A potential problem with this method of collection is that, unlike a urine test, this type of blood sample is just a snapshot in time. The levels of the various hormones in the bloodstream can change from moment to moment and from day to day. If a perimenopausal woman’s blood sample indicates that her estradiol level is in the normal range, it does not necessarily mean that she has a normal amount all day long. She could be higher or lower at any given time throughout the day or throughout the month.

However, another form of blood collection called blood spot testing can account for hormone fluctuations because it can easily be scheduled for specific days of the month, such as before or after hormone therapies, or specific times of the day, such as before or after meals or other medications.

For blood spot testing, a patient collects drops of their own blood from a finger prick onto a card for submission to a lab for analysis. With this method, results are typically comparable to those from serum tests, but without the cost and inconvenience of a lab visit, so it is rapidly gaining in popularity.

With both types of blood tests, the hormones are typically analyzed using techniques such as radioimmunoassay. Unlike the mass spectroscopy used in the urine analysis, these methods may or may not be hormone specific.

Because there are so many steroidal hormones and they are all so close to each other in chemical structure, there might be “spill over” from one hormone to other similar hormones, depending on the process that the lab uses.

For example, a lab kit for testosterone analysis might report that 50% of the hormone analyzed may be dihydrotestosterone. In the case of a male concerned about prostate enlargement, a more specific distinction may be necessary or important.