Aldosterone: An Evidence-Based Guide for Patients

Aldosterone is a hormone made by the adrenal glands that helps the body balance sodium, potassium, and fluid levels, which in turn supports healthy blood pressure. When aldosterone is too high or too low, it can contribute to problems such as high blood pressure, weakness, dehydration, or abnormal blood test results.

Overview: what aldosterone does in the body

Aldosterone is a hormone produced by the outer layer of the adrenal glands, which sit on top of the kidneys. Its main job is to help the body keep the right balance of sodium and potassium. By acting on the kidneys, aldosterone tells the body to retain sodium and water while excreting potassium into the urine. This balance helps maintain blood volume and supports normal blood pressure.

Aldosterone works closely with a broader system called the renin-angiotensin-aldosterone system, or RAAS. When blood pressure drops, blood volume is low, or the body needs to conserve salt, this system signals the adrenal glands to release more aldosterone. In healthy people, this response is tightly controlled and changes from moment to moment depending on the body’s needs.

Problems arise when aldosterone production is either too high or too low. Excess aldosterone can drive high blood pressure and lower potassium levels. Too little aldosterone can make it difficult to hold onto sodium and water, which may lead to dizziness, dehydration, and high potassium. Because these symptoms can overlap with many other conditions, proper testing is important before drawing conclusions.

How high or low aldosterone can affect health

High aldosterone is often discussed in relation to primary aldosteronism, a condition in which the adrenal glands make too much of the hormone. This can happen because of an adrenal nodule or enlargement of both adrenal glands. In some people, high aldosterone is one of the hidden causes of difficult-to-control high blood pressure, even when there are no obvious symptoms.

Low aldosterone is less common but can also be important. It may occur in adrenal insufficiency, certain kidney disorders, or as a result of some medicines. When aldosterone is low, the body may lose too much sodium and water and retain too much potassium. This can lead to fatigue, low blood pressure, lightheadedness, and sometimes more serious electrolyte problems.

Aldosterone problems may also occur alongside other endocrine conditions. For example, some people being evaluated for Cushing syndrome or adrenal gland disorders may have hormone testing that includes aldosterone, depending on symptoms and blood pressure findings. The key point is that aldosterone is not usually interpreted alone; doctors look at the full clinical picture, including blood pressure, potassium levels, kidney function, and other hormones.

Symptoms and signs of an aldosterone imbalance

Many people with abnormal aldosterone levels do not notice clear symptoms at first. In fact, high aldosterone is sometimes discovered during an evaluation for high blood pressure or low potassium on routine blood work. When symptoms do occur, they are often related to changes in blood pressure or electrolytes rather than to the hormone itself.

Possible signs of high aldosterone can include persistent high blood pressure, headaches, muscle weakness, muscle cramps, fatigue, increased thirst, and frequent urination. Some people develop tingling, palpitations, or constipation when potassium becomes too low. However, these symptoms are not specific and can have many causes.

Possible signs of low aldosterone include low blood pressure, dizziness when standing, salt craving, nausea, dehydration, weakness, and high potassium on blood tests. In some people, low aldosterone occurs with low cortisol as part of adrenal insufficiency, which may also cause weight loss, abdominal symptoms, and skin changes. Because symptoms can be subtle, a doctor may recommend testing based on blood pressure patterns, family history, medications, and lab results.

• High aldosterone may be suspected in resistant hypertension or unexplained low potassium.
• Low aldosterone may be suspected in dehydration, low blood pressure, or high potassium.
• Symptoms alone cannot confirm the diagnosis; lab testing is needed.

Causes and risk factors

The causes of high aldosterone are usually divided into primary and secondary forms. In primary aldosteronism, the adrenal glands themselves produce too much hormone. Common causes include a benign adrenal adenoma or overactivity of both adrenal glands. Secondary increases in aldosterone happen when another problem, such as reduced blood flow to the kidneys, heart failure, liver disease, or severe dehydration, stimulates the RAAS system.

Risk factors that may prompt doctors to consider aldosterone-related testing include high blood pressure that is hard to control, blood pressure that starts at a young age, a family history of early stroke or primary aldosteronism, and low potassium without a clear explanation. Some people have normal potassium despite excess aldosterone, so the absence of low potassium does not rule it out.

Low aldosterone can develop in people with adrenal insufficiency, certain forms of kidney disease, diabetes-related changes that affect renin production, or the use of medications that interfere with hormone pathways. Examples include some blood pressure medicines, anti-inflammatory drugs, and heparin. Doctors also consider whether the adrenal glands have been affected by infection, autoimmune disease, bleeding, or inherited conditions. Evaluation is individualized because the same blood test result can have different meanings in different clinical settings.

How aldosterone is tested and diagnosed

Diagnosing an aldosterone disorder usually starts with a careful history, physical examination, and review of medications. Because many drugs can affect aldosterone or renin levels, doctors may adjust treatment before testing when it is safe to do so. Blood pressure measurements, kidney function, and sodium and potassium levels are also part of the assessment.

The most common screening test for excess aldosterone is the aldosterone-to-renin ratio. This blood test compares aldosterone with renin, another hormone involved in blood pressure regulation. A suspicious result does not by itself confirm the diagnosis, but it helps identify who may need further evaluation. Doctors may then order confirmatory testing, such as salt-loading tests or 24-hour urine studies, depending on the situation.

If primary aldosteronism is confirmed, imaging such as MRI or CT may be used to look at the adrenal glands, but imaging alone does not always show which gland is responsible. In selected patients, specialists may recommend adrenal vein sampling, a more specialized test that compares hormone levels from each adrenal gland. When low aldosterone is suspected, testing may also include cortisol and other adrenal hormones to look for Addison's disease or related conditions. In centers with endocrine and imaging expertise, a tailored work-up can help guide the safest treatment plan.

Treatment options for aldosterone-related conditions

Treatment depends on whether aldosterone is too high or too low and on the underlying cause. For high aldosterone due to overactivity in both adrenal glands, doctors often use medicines called mineralocorticoid receptor blockers. These drugs help counter the hormone’s effect on the kidneys and can improve blood pressure and potassium levels. Treatment also includes monitoring kidney function, electrolytes, and blood pressure over time.

When excess aldosterone comes from a single adrenal gland problem, surgery may be considered. After careful testing to show which gland is affected, some patients may benefit from adrenalectomy. The goal is to reduce hormone overproduction and improve blood pressure control, although some people still need blood pressure medication afterward.

Low aldosterone is treated by addressing the cause. This may include adjusting medications, treating adrenal insufficiency, and carefully managing fluids and electrolytes. Some people need hormone replacement when the adrenal glands are not making enough hormones overall. Because management can involve both kidney and hormone issues, patients may be evaluated by endocrinology and nephrology specialists. In complex cases, doctors may also coordinate imaging and endocrine testing through services such as endocrinology and metabolic disease care.

Self-care, blood pressure management, and everyday considerations

Self-care does not replace medical treatment, but it can support safer day-to-day management. People who have high aldosterone or suspected primary aldosteronism should take blood pressure medicine exactly as prescribed and attend follow-up appointments for repeat blood tests. Sudden changes in medication, especially blood pressure medicines or diuretics, should not be made without medical advice.

Dietary guidance depends on the individual diagnosis. In many people with high blood pressure, reducing excess sodium intake can be helpful, but advice should be personalized, particularly if low aldosterone or adrenal insufficiency is present. Some patients need guidance about potassium-rich foods, while others need closer monitoring of potassium rather than dietary restriction. A clinician or dietitian can help tailor advice to lab results and overall health.

Home blood pressure monitoring can be useful, especially if blood pressure has been difficult to control. Patients should bring readings to appointments and report symptoms such as worsening weakness, fainting, severe cramps, or palpitations. For international patients who need coordinated endocrine, imaging, and surgical assessment, Acibadem International’s multidisciplinary specialists in JCI-accredited hospitals diagnose and treat adrenal and blood pressure-related conditions with individualized care planning.

When to seek medical care

Medical advice is appropriate if a person has high blood pressure that remains elevated despite treatment, repeated low potassium, unexplained dizziness, or abnormal sodium and potassium blood tests. A clinician can decide whether aldosterone testing is relevant and whether another endocrine, kidney, or cardiovascular condition may be involved.

Prompt medical assessment is especially important for severe weakness, fainting, chest symptoms, confusion, or signs of significant dehydration. These symptoms can reflect a serious electrolyte imbalance or another urgent condition. People with known adrenal disease should follow their doctor’s instructions closely and seek help quickly if symptoms suddenly worsen.

Because aldosterone disorders can be subtle, early evaluation can be valuable even when symptoms seem mild. A structured work-up can help distinguish ordinary high blood pressure from a potentially treatable hormone-related cause and can reduce the risk of long-term complications from uncontrolled blood pressure or electrolyte imbalance.

Frequently asked questions

What is aldosterone in simple terms?

Aldosterone is a hormone made by the adrenal glands above the kidneys. It helps the body control salt, potassium, and water balance, which supports normal blood pressure.

What happens if aldosterone is too high?

High aldosterone can make the body retain too much sodium and lose too much potassium. This often leads to high blood pressure and may cause weakness, cramps, fatigue, or frequent urination.

What happens if aldosterone is too low?

Low aldosterone can cause the body to lose sodium and water and hold onto potassium. This may lead to low blood pressure, dizziness, dehydration, weakness, and abnormal blood test results.

How is aldosterone tested?

Doctors usually start with blood tests, especially the aldosterone-to-renin ratio, along with sodium and potassium levels. Depending on the results, they may order confirmatory tests, urine tests, or imaging of the adrenal glands.

Can aldosterone cause high blood pressure?

Yes. Too much aldosterone is a recognized cause of secondary high blood pressure, especially when blood pressure is resistant to treatment or potassium is low.

Is an aldosterone problem treatable?

In many cases, yes. Treatment may include medications that block aldosterone, treatment of adrenal insufficiency, or surgery if a single adrenal gland is overproducing the hormone.

References

• National Institute of Diabetes and Digestive and Kidney Diseases
• Endocrine Society
• American Heart Association
• National Adrenal Diseases Foundation
• Merck Manual Consumer Version

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.