Aldosterone LC MS MS test (blood) Biomarker Testing
It measures aldosterone to assess salt-and-fluid hormone balance and blood pressure drivers, with convenient ordering and Quest lab access via Vitals Vault.
With Vitals Vault, you have access to a comprehensive range of biomarker tests.
Aldosterone is a hormone that helps your body hold onto sodium, release potassium, and manage fluid volume. Because fluid volume affects blood pressure, aldosterone is often part of the “why is my blood pressure acting this way?” workup.
An Aldosterone LC MS MS test measures aldosterone in your blood using liquid chromatography–tandem mass spectrometry (LC‑MS/MS), a method designed to improve analytical specificity. Your number is most useful when it is interpreted alongside your symptoms, blood pressure pattern, potassium level, and often renin (another hormone in the same pathway).
This test can support clinician-directed decisions, but it cannot diagnose a condition by itself. The context—medications, posture, salt intake, and timing—can change the result as much as an underlying health issue can.
Do I need a Aldosterone LC MS MS test?
You may want aldosterone testing if you have high blood pressure that is hard to control, especially if it started at a younger age, requires multiple medications, or runs strongly in your family. It is also commonly considered when you have low potassium (hypokalemia), muscle weakness, frequent urination, or unexplained headaches.
Aldosterone can also be relevant if you have episodes of dizziness when standing, salt cravings, or low blood pressure—particularly if there is concern for reduced adrenal hormone output. In those situations, aldosterone is usually interpreted with other adrenal markers and electrolytes rather than in isolation.
If you are already being evaluated for suspected primary aldosteronism (a common, treatable cause of secondary hypertension), your clinician may prefer aldosterone plus renin so they can calculate the aldosterone-to-renin ratio (ARR). If you are monitoring treatment—such as mineralocorticoid receptor blockers or after an adrenal procedure—repeat testing can help show whether the pathway is moving in the right direction.
This is a CLIA laboratory test; results are for education and clinician-guided care and are not a standalone diagnosis.
Lab testing
Ready to order aldosterone testing and schedule your draw through Quest?
Schedule online, results typically within about a week
Clear reporting and optional clinician context
HSA/FSA eligible where applicable
Get this test with Vitals Vault
Vitals Vault lets you order an Aldosterone LC MS MS blood test without needing a separate lab visit referral. After you order, you can schedule your draw through the Quest network and view your results in one place.
Because aldosterone is sensitive to real-world variables (like blood pressure meds, salt intake, and whether you were sitting or standing), interpretation matters. PocketMD can help you prepare questions for your clinician, understand common next steps (like adding renin, electrolytes, or cortisol testing), and decide when a retest is worth doing.
If your result suggests a pattern that needs broader mapping—such as blood pressure plus potassium issues, adrenal concerns, or medication effects—you can add companion labs through Vitals Vault so your follow-up is based on data rather than guesswork.
- Order online and draw at Quest locations
- Clear, plain-language result context in PocketMD
- Easy re-testing to confirm trends after medication or lifestyle changes
Key benefits of Aldosterone LC MS MS testing
- Helps explain certain blood pressure patterns by assessing a key salt-and-fluid regulating hormone.
- Supports screening for primary aldosteronism when paired with renin and potassium.
- Adds context when potassium is low or fluctuating without a clear cause.
- Can help distinguish medication effects from underlying hormone-driven changes when interpreted carefully.
- Useful for monitoring response to mineralocorticoid receptor blockers or other clinician-directed treatment plans.
- LC‑MS/MS methodology improves analytical specificity compared with some immunoassays in challenging samples.
- Creates a baseline you can trend over time, especially when you standardize timing, posture, and prep.
What is Aldosterone LC MS MS?
Aldosterone is a steroid hormone made by the adrenal glands (small glands that sit on top of your kidneys). Its main job is to tell your kidneys how much sodium to keep, how much water to retain with that sodium, and how much potassium to excrete. When aldosterone is higher than your body needs, you can retain more sodium and water, which can raise blood pressure and sometimes lower potassium.
The “LC MS MS” part describes the measurement method: liquid chromatography separates compounds in the sample, and tandem mass spectrometry detects aldosterone based on its mass-to-charge signature. In plain terms, this approach is designed to be more specific, reducing the chance that similar-looking molecules interfere with the measurement.
Aldosterone does not act alone. It is part of the renin–angiotensin–aldosterone system (RAAS), which responds to blood volume, kidney blood flow, and sodium intake. That is why aldosterone is often interpreted alongside renin (or plasma renin activity), electrolytes, and blood pressure readings taken in a consistent way.
Why clinicians often pair aldosterone with renin
Aldosterone can be “appropriately high” if renin is high (for example, when your body is trying to hold onto salt and water). It can be “inappropriately high” if renin is low, which is one of the patterns that raises concern for primary aldosteronism. The ratio between aldosterone and renin (ARR) is often more informative than either number alone.
Blood vs urine aldosterone
A blood aldosterone test is a snapshot at one point in time and is sensitive to posture and timing. Some evaluations use 24-hour urine aldosterone after a specific salt-loading protocol. Your clinician chooses the approach based on the question being asked and whether confirmatory testing is needed.
What do my Aldosterone LC MS MS results mean?
Low aldosterone levels
A low aldosterone result can show up when your body is not signaling for sodium retention, or when aldosterone production is reduced. In real life, this may align with low blood pressure, dizziness on standing, dehydration, or high potassium, but many people with low aldosterone have nonspecific symptoms. Some medications and higher salt intake can suppress aldosterone, so a low value is not automatically a sign of adrenal disease. If there is clinical concern, your clinician may look at renin, cortisol, ACTH, and electrolytes to clarify the picture.
In-range (expected) aldosterone levels
An in-range aldosterone result generally suggests your aldosterone output is appropriate for the conditions under which the sample was collected. Because aldosterone shifts with posture, time of day, and sodium intake, “normal” is most meaningful when your test prep and collection conditions are documented. If you are evaluating high blood pressure or potassium issues, an in-range aldosterone does not rule out RAAS-related problems on its own. Pairing the result with renin and potassium often provides the more actionable interpretation.
High aldosterone levels
A high aldosterone result can be a clue that your body is retaining sodium and excreting potassium more than it should. One important pattern is high aldosterone with low renin, which can suggest primary aldosteronism and is a common, treatable contributor to hypertension. Another pattern is high aldosterone with high renin, which can occur when the body is responding to reduced effective blood volume or certain kidney-related signals. Because false elevations can happen from collection conditions or medications, clinicians often confirm with repeat testing and/or additional RAAS-focused labs.
Factors that influence aldosterone
Aldosterone is highly sensitive to posture (standing tends to raise it), time of day, stress, and recent sodium intake. Many blood pressure medications can change aldosterone and renin in different directions, which can affect screening ratios; do not stop medications without clinician guidance. Dehydration, vomiting/diarrhea, and diuretics can also shift results by changing fluid volume and electrolytes. Even how long you were seated before the draw can matter, so consistent prep improves the value of trending.
What’s included
- Aldosterone, Lc/Ms/Ms
Frequently Asked Questions
Do I need to fast for an aldosterone blood test?
Fasting is not always required, but preparation matters more than food for many people. Posture (seated vs standing), time of day, and salt intake can change aldosterone. Follow the collection instructions provided with your order, and ask your clinician whether you should standardize morning timing and a seated rest period.
What is the difference between aldosterone LC‑MS/MS and an aldosterone immunoassay?
Both aim to measure aldosterone, but LC‑MS/MS is designed to be more analytically specific by identifying aldosterone based on its mass signature. Some immunoassays can be more prone to interference from similar steroid molecules in certain situations. Your clinician will still interpret either method in context of renin, potassium, medications, and collection conditions.
Should aldosterone be tested with renin?
Often, yes. The aldosterone-to-renin ratio (ARR) is a common screening tool when primary aldosteronism is a concern, especially in resistant hypertension or low potassium. Testing aldosterone alone can be harder to interpret because aldosterone may be appropriately high or low depending on renin-driven signals.
What medications can affect aldosterone results?
Many blood pressure medications can affect aldosterone and/or renin, including diuretics, ACE inhibitors, ARBs, beta blockers, and mineralocorticoid receptor blockers (like spironolactone or eplerenone). Oral contraceptives, licorice products, and some steroids can also influence the pathway. Do not change prescriptions for testing without clinician supervision; instead, document what you take and when.
What does high aldosterone with low renin mean?
That pattern can suggest aldosterone is being produced “out of proportion” to the usual RAAS signal, which raises suspicion for primary aldosteronism. It does not confirm a diagnosis by itself, because collection conditions and medications can distort the pattern. Clinicians typically repeat testing under standardized conditions and may order confirmatory tests and imaging only when appropriate.
When should I retest aldosterone?
Retesting is commonly considered if your first result was borderline, if the draw conditions were not standardized, or after a medication change that could shift RAAS hormones. Your clinician may also retest to monitor treatment response. As a practical rule, aim to repeat under similar timing and posture so the comparison is meaningful.