⚠️ Educational only. LabPlain does not provide medical advice or diagnosis. Always discuss your specific results with your healthcare provider.
What this test measures
Aldosterone is a vital hormone produced by the outer layer of your adrenal glands, located on top of each kidney. Its primary role is to manage the balance of water and essential salts (sodium and potassium) in your body. By signaling your kidneys to retain sodium and excrete potassium, aldosterone directly influences your overall blood volume and blood pressure.
Your body tightly regulates aldosterone through a complex chemical path involving the kidneys, liver, and pituitary gland. When blood pressure drops or sodium levels fall, the kidneys release an enzyme called renin, which triggers a sequence that tells your adrenal glands to produce more aldosterone.
Doctors typically order this test to evaluate cases of unexplained high blood pressure (especially if standard medications aren't working), check for adrenal gland disorders, or investigate unusual imbalances in your blood potassium levels.
Normal reference range
Sitting Upright: 3–28 ng/dL | Lying Down (Supine): 2–16 ng/dL
Aldosterone levels vary significantly based on your body posture during the blood draw. Gravity shifts blood volume, which changes how much renin and aldosterone your body produces. Levels are typically higher when you have been sitting or standing compared to when you have been lying flat.
Dietary salt intake and specific blood pressure medications also shift these numbers dramatically. Always check the baseline reference numbers listed on your specific lab report.
⏰ Why preparation matters
Because salt intake, posture, and medications heavily interact with aldosterone, your doctor may give you precise instructions before your test. This can include sitting quietly for 15 to 30 minutes right before the draw or temporarily adjusting your medication schedule.
What your result might indicate
↑ If High
Elevated aldosterone may indicate primary aldosteronism (Conn's syndrome), usually caused by a benign tumor on the adrenal glands. It can also point to secondary aldosteronism, which may stem from kidney artery narrowing, heart failure, or a low-salt diet.
↓ If Low
Low aldosterone levels may indicate adrenal insufficiency (such as Addison's disease), a condition where the adrenal glands are damaged. It can also be associated with high-salt diets, specific genetic conditions, or certain types of kidney dysfunction.
Symptoms associated with abnormal aldosterone
↑ High Aldosterone Symptoms
Persistent high blood pressure
Frequent muscle cramps or spasms
Muscle weakness or fatigue
Increased thirst and frequent urination
Headaches or blurred vision
Temporary numbness or tingling sensations
↓ Low Aldosterone Symptoms
Low blood pressure or dizziness upon standing
Chronic fatigue and muscle weakness
Unexplained weight loss
Strong cravings for salty foods
Nausea, vomiting, or occasional diarrhea
Dehydration or low blood volume
Common causes of abnormal aldosterone
What can raise aldosterone?
The most common medical cause of primary overproduction is a small, non-cancerous tumor in an adrenal gland, or general enlargement (hyperplasia) of both adrenal glands. This is often referred to as Conn's syndrome.
Secondary high aldosterone happens when another condition outside the adrenal glands forces them to work harder. This can occur with reduced blood flow to the kidneys (renal artery stenosis), congestive heart failure, liver cirrhosis, severe dehydration, or a diet very low in sodium.
What can lower aldosterone?
Low levels are most frequently linked to primary adrenal insufficiency (Addison's disease), where autoimmune damage stops the adrenal glands from producing multiple hormones.
It can also be caused by a medical state known as hyporeninemic hypoaldosteronism, often seen in people with kidney damage from long-standing diabetes, where the kidneys fail to produce enough renin to jumpstart aldosterone production.
Tests often ordered alongside aldosterone
Aldosterone levels are highly interdependent on other biomarkers. Your provider will often order:
Plasma Renin Activity (PRA) — measures the enzyme that triggers aldosterone; comparing the two via an Aldosterone-to-Renin Ratio (ARR) is standard for diagnosing adrenal issues
Potassium — high aldosterone drives potassium down, so checking this essential electrolyte is crucial
Sodium — tracks salt balance and fluid retention shifts in your bloodstream
Cortisol — another major adrenal hormone evaluated if general adrenal gland dysfunction is suspected
Kidney Function Panel (BUN & Creatinine) — helps check if kidney issues are driving secondary aldosterone changes
What to do next
An isolated out-of-range aldosterone level does not lead directly to a diagnosis. Because it responds to your daily diet, your posture, and your current medications, your provider will look at the whole picture. They will likely review your blood pressure trends and electrolyte levels, and they may ask you to repeat the test under strict resting conditions or refer you to an endocrinologist for specialized interpretation.
Questions to ask your doctor
01Was my blood drawn while sitting upright or lying down, and how does that affect these results?
02How does my potassium level compare to my aldosterone level?
03Could any of my current blood pressure medications have skewed this measurement?
04Should we calculate an Aldosterone-to-Renin Ratio (ARR) based on my bloodwork?
05Do I need to modify my salt intake or adjust any prescriptions before running a repeat test?
06Is a referral to an endocrinologist recommended for further diagnostic evaluations?
Frequently asked questions
Can a high-salt diet cause abnormal aldosterone levels?
Yes. Eating a high amount of salt increases your blood volume and sodium levels naturally. Your body responds normally by lowering aldosterone production to help flush out the extra salt. Conversely, a very low-salt diet will elevate your aldosterone levels.
What is the aldosterone-to-renin ratio (ARR)?
The ARR is a screening tool used by doctors to find the underlying cause of high blood pressure. By looking at the math ratio between aldosterone and renin, providers can determine if your high blood pressure is coming from an independent adrenal gland issue or from kidney signals.
Why does blood pressure medication affect my results?
Many blood pressure drugs work by blocking the hormones or paths that regulate aldosterone. Beta-blockers, ACE inhibitors, and diuretics can falsely raise or lower your test results, which is why your doctor must know exactly what you take.
Is primary aldosteronism curable?
In many cases, it is highly treatable or curable. If it is caused by a benign tumor on just one adrenal gland, surgically removing that single gland often brings blood pressure and potassium back to normal. If both glands are involved, it is typically managed successfully with specific medications.