What is Aldosterone?
Adrenal glands, located at the top of each kidney, produce a hormone called “Aldosterone,” which is involved in the regulation of blood pressure, maintaining electrolyte balance, i.e., sodium and potassium, by signaling the kidneys to excrete potassium and retain sodium to maintain fluid levels that regulate the normal blood pressure.
An aldosterone test is conducted for the measurement of aldosterone levels in the blood which helps in the diagnosis and monitoring of diseases associated with an imbalance of aldosterone levels, its production and function, as well as the adrenal gland functioning.
How is the Test Performed?
The Aldosterone test is a straightforward test involving the withdrawal of the blood;
Preparation
- Avoid taking black licorice 2 weeks before the test
- Stop taking any medications that may interfere with aldosterone levels if instructed by the doctor
Avoid high salt intake - Posture plays an important role in the levels of aldosterone as it changes when you’re standing or lying down.
Be upright for at least 2 hours before the test.
Collection
- A trained technician draws blood from your vein typically from the arm.
- The sample is then placed in a tube to prevent contamination and degradation of the sample.
Lab Analysis
The sample is then sent to the laboratory for analysis of aldosterone in the blood.
Techniques like immunoassay and high-performance liquid chromatography (HPLC) are used in the laboratory for analysis.
What are the symptoms that prompt this test?
An aldosterone test is suggested for patients experiencing the following symptoms suggestive of adrenal gland disorders and imbalances in the electrolyte;
Symptoms of High Aldosterone
- Unmanageable high blood pressure
- Muscle weakness and cramps
Fatigue - Urinating frequently
- General weakness
- Extreme thirst
Symptoms of Low Aldosterone
- Irregular heart rhythms due to high potassium
- Lightheadedness when standing up
- Low blood pressure
- Dehydration
- Salt cravings
What are Normal Ranges for This Test?
The levels of the aldosterone hormone vary according to age, gender, posture, and intake of sodium. The reference ranges are given below;
- 1-12 months old – 8 to 110 ng/dL.
- 1-5 years old –less than 36 ng/dL
- 6-9 years old – less than 24 ng/dL
- 10-11 years old – less than 15 ng/dL
- 12-14 years old– less than 22 ng/dL
- 15-17 years old – 0 to 32.0 ng/dL
- 18-99 years old – 1 to 35.4 ng/dL
**The reference ranges vary depending on the laboratory and the methodology used. Individuals must consult their healthcare provider for correct interpretation of the results.**
What Happens if Test Results Show Abnormal Levels?
If aldosterone levels are not in the normal reference range it indicates the presence of underlying disease. High aldosterone level is mostly common whereas low levels are rare.
High Aldosterone Level
High levels of aldosterone indicate the presence of hyperaldosteronism and it comprises two types;
- Primary hyperaldosteronism caused by to adrenal gland tumor or hyperplasia
- Secondary hyperaldosteronism caused due to liver cirrhosis, renal artery stenosis, and heart failure, these conditions reduce the blood flow to the kidneys therefore affecting the adrenal gland.
Low Aldosterone Levels
- Addison’s disease leads to low or no production of the hormone aldosterone
- Congenital adrenal hyperplasia, a genetic disorder that affects the adrenal glands
- Use of certain medications including NSAIDS, and ACE inhibitors Your doctor may recommend follow-up tests including renin activity, imaging studies, and salt loading tests. After the diagnosis of the disease, various treatment options are integrated including dietary changes, surgery, hormone replacement therapy, and medication.
