Hyperaldosteronism
Excess aldosterone causing high blood pressure
Quick Facts
- Type: Hormonal (endocrine) condition
- Hormone involved: Aldosterone (from the adrenal glands)
- Main effect: High blood pressure, sometimes low potassium
- Often: An overlooked cause of resistant high blood pressure
Overview
Aldosterone is a hormone made by the adrenal glands, which sit on top of the kidneys. It helps control blood pressure by signaling the kidneys to hold on to sodium (salt) and water and to remove potassium. In hyperaldosteronism, the body makes too much aldosterone, which raises blood pressure and can lower the level of potassium in the blood.
When the problem starts in the adrenal glands themselves, it is called primary aldosteronism (sometimes Conn syndrome). When it happens because something outside the adrenal glands triggers extra aldosterone, it is called secondary hyperaldosteronism. Primary aldosteronism is an important and treatable cause of high blood pressure that is often overlooked, especially when blood pressure is hard to control with usual medicines.
Symptoms
Many people have few specific symptoms, and the condition is often discovered during investigation of high blood pressure.
- High blood pressure that may be difficult to control
- Symptoms of low potassium, when present, such as muscle weakness, cramps, and fatigue
- Increased thirst and frequent urination
- Headaches
- Occasionally, episodes of severe muscle weakness
Because the symptoms can be vague or absent, hyperaldosteronism is frequently missed unless it is specifically tested for.
Causes
The causes differ between the primary and secondary forms.
- Primary aldosteronism: The adrenal glands themselves overproduce aldosterone. This may be due to a benign tumor in one adrenal gland (an aldosterone-producing adenoma) or to enlargement of both adrenal glands.
- Secondary hyperaldosteronism: Something outside the adrenal glands drives extra aldosterone, such as narrowing of the arteries to the kidneys, heart failure, liver disease, or certain medicines.
Distinguishing primary from secondary forms is important because the treatments differ.
Risk Factors
- High blood pressure that is difficult to control despite several medicines
- High blood pressure together with an unexplained low potassium level
- High blood pressure at a relatively young age
- An adrenal nodule found incidentally on a scan
- A family history of primary aldosteronism or early high blood pressure
Diagnosis
Diagnosis involves blood tests, sometimes followed by imaging and specialized procedures.
- Screening blood tests: Measuring aldosterone and a related hormone called renin, and comparing their ratio.
- Confirmatory tests: Tests that check whether aldosterone stays high when it should normally be suppressed.
- Imaging: A CT scan of the adrenal glands to look for a tumor or enlargement.
- Adrenal vein sampling: A specialized procedure to determine whether one or both adrenal glands are responsible, which guides treatment.
Treatment
Treatment depends on whether one or both adrenal glands are overactive and on the underlying cause.
- Surgery: When a single adrenal gland with a tumor is responsible, removing that gland can cure or greatly improve high blood pressure and correct potassium.
- Medication: When both glands are involved or surgery is not suitable, medicines that block the effect of aldosterone (mineralocorticoid receptor antagonists) lower blood pressure and raise potassium.
- Treating secondary causes: Addressing the underlying problem, such as a narrowed kidney artery or heart failure.
- Blood pressure and potassium monitoring: Ongoing follow-up to keep both in a healthy range.
Prevention
- Hyperaldosteronism cannot usually be prevented, but its complications can be reduced
- Testing for it in people with hard-to-control high blood pressure or unexplained low potassium allows earlier treatment
- Keeping blood pressure well controlled lowers the risk of heart, kidney, and blood vessel damage
- Following up regularly and taking prescribed medicines as directed
When to See a Doctor
See a doctor if your blood pressure is high and difficult to control, if you have high blood pressure with a low potassium level, or if you develop muscle weakness, cramps, excessive thirst, and frequent urination. Ask whether testing for hyperaldosteronism is appropriate, as it is a treatable cause of high blood pressure. Seek urgent care for severe muscle weakness, an irregular heartbeat, or very high blood pressure with symptoms such as chest pain, severe headache, or shortness of breath.
Frequently Asked Questions
What is hyperaldosteronism?
It is a condition in which the body makes too much aldosterone, a hormone that controls salt, water, and potassium balance. The excess raises blood pressure and can lower potassium. The primary form starts in the adrenal glands and is a treatable cause of high blood pressure.
How does hyperaldosteronism cause high blood pressure?
Aldosterone tells the kidneys to retain sodium and water, which increases the volume of fluid in the blood vessels and raises blood pressure. Too much aldosterone keeps blood pressure elevated and is often resistant to standard medicines.
Why is hyperaldosteronism often missed?
Many people have few specific symptoms, and potassium is not always low, so the condition can look like ordinary high blood pressure. It is usually found only when doctors specifically test for it, often in people with hard-to-control blood pressure.
Can hyperaldosteronism be cured?
When a single adrenal gland with a tumor is the cause, surgically removing that gland can cure or greatly improve the high blood pressure and correct potassium. When both glands are involved, medicines that block aldosterone control it effectively.
Who should be tested for hyperaldosteronism?
Testing is recommended for people whose blood pressure is hard to control despite several medicines, who have high blood pressure with unexplained low potassium, who develop high blood pressure young, or who have an adrenal nodule found on a scan.
References
- MedlinePlus, U.S. National Library of Medicine. Hyperaldosteronism.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Adrenal disorders.
- Mayo Clinic. Primary aldosteronism.