Aldosterone Test – Its Role in the Management of Hypertension

Max Lab

Jan 17, 2024

Hypertension, also known as high blood pressure, is one of the most common health concerns among people nowadays. The condition can affect the heart, brain, eyes, kidneys, and blood vessels and is a condition that may not display many symptoms. While high blood pressure may be caused by unhealthy lifestyle habits like smoking, having a poor diet, and lack of exercise, in most cases, the underlying cause remains unknown. However, for one in 15 people who may have hypertension, the condition is caused by an aldosterone hormone imbalance. Understanding aldosterone levels in the blood is important for the diagnosis of conditions like primary aldosteronism, which is a common cause of secondary hypertension.

What is Hypertension?

Hypertension is a common condition where the force of blood pushing against the artery walls is consistently high. It can damage the arteries, and lead to serious health complications, like a stroke or heart attack. The normal range for blood pressure is generally considered to be around 120/80 mmHg.

There are two main categories of hypertension:

• Primary Hypertension: This is the most common type of hypertension, and the exact cause behind this condition is often unknown. It's most likely a combination of genetic and environmental factors, such as diet, exercise, stress, and/or smoking.
• Secondary Hypertension: This type of hypertension is caused by an underlying medical condition, such as kidney disease, high aldosterone levels, sleep apnoea, or thyroid disorders.

Symptoms of Hypertension

Hypertension is often called a “silent killer” by health professionals, as it generally does not display any symptoms, even when blood pressure readings reach dangerously high levels. That’s why it's very important to get one’s blood pressure checked regularly, even if feeling fine. Left untreated, hypertension can lead to serious health problems. In cases where the condition does display symptoms, they may include:

• Headache
• Bleeding from the nose
• Shortness of breath
• Dizziness
• Blurry vision

What is Aldosterone?

Aldosterone (ALD) is a type of hormone that is produced by the adrenal glands, located above the kidney. The function of aldosterone in the body is to manage the level of potassium and sodium in the blood. Sodium and potassium are electrolytes that maintain the fluid and blood volume within the body and thus help the body function properly.

The ALD hormone is also classified as a mineralocorticoid, highlighting its pivotal role in regulating electrolyte balance within the body. The adrenal glands, situated atop each kidney, release aldosterone in response to various signals. The main function of aldosterone is to maintain blood pressure and fluid balance within the body.

The Relationship between Aldosterone and Hypertension

Although hypertension can be caused because of various reasons, one crucial factor that may be responsible for it is an excess of aldosterone (ALD) in the body. As mentioned above, aldosterone plays a crucial role in regulating the salt and water balance in the body. When there is an excess of aldosterone, it can lead to the body retaining both salt and water. This increased fluid volume can also lead to a rise in blood pressure.

High levels of ALD in the blood is known as hyper aldosterone. Hyper aldosterone can cause high blood pressure and low potassium levels in the blood. There are two main types of hyper aldosteronism:

1. Primary Aldosteronism, also known as Conns disease, is usually caused by the presence of a non-cancerous tumour in one or both adrenal glands. The tumour is responsible for the high production of ALD.
2. Secondary Aldosteronism: Secondary aldosteronism refers to the case where there is some other underlying problem in the body that causes the adrenal glands to release ADL at higher levels.

In case of high blood pressure or hypertension, a medical professional may recommend a thorough assessment for hyperaldosteronism. This condition, characterised by excessive aldosterone production, can be effectively diagnosed through an aldosterone test.

What is the Aldosterone Test?

The aldosterone test is a diagnostic test that is used to measure the levels of aldosterone (ALD) in the blood or urine. This test is crucial for assessing the functioning of the adrenal glands and for diagnosing conditions related to aldosterone imbalance.

Doctors may also prescribe a renin test along with an ALD test. Renin is a hormone that is secreted by the kidney. This hormone signals the adrenal glands to produce aldosterone, controlling the production of the ALD hormone. The combination of ALD and renin tests is also referred to as the aldosterone-plasma renin test, aldosterone-renin ratio test, or aldosterone urine test. Measuring the levels of ALD and renin hormones helps doctors understand whether abnormal ALD levels are being caused by a problem in the functioning of kidneys or adrenal glands or by some other health issue in the body.

How the Aldosterone Test is Performed

The aldosterone test is done using either a blood or urine sample. The aldosterone-renin ratio test, or the test that compares ALD and renin levels uses a blood sample for examination. During the blood test, the phlebotomist collects a blood sample from a vein in the arm using a needle. The needle may cause a slight pricking or striking sensation. The whole process takes around 5 minutes, and then the blood sample is sent to the laboratory for analysis.

Management of Hypertension Caused by Aldosterone Imbalance

Hypertension which is caused by high levels of the aldosterone hormone or hyper aldosterone, can be treated by managing one’s blood pressure. In the case of primary aldosteronism or Conns disease, caused by an adrenal gland tumour, the doctor may recommend removing the tumour. In some cases, the tumour may also be removed through medication. Even after the removal of the tumour, one may still have a case of high blood pressure and may need medication to manage it.

The treatment of secondary aldosteronism is usually done by managing the blood pressure using medication. Some lifestyle changes that a doctor may recommend are:

• Frequent exercising
• Limiting alcohol consumption
• Quitting smoking

The Role of Aldosterone Testing in Hypertension Management

As aldosterone plays a crucial role in blood pressure management in the body, the aldosterone test is an important diagnostic tool in the diagnosis, treatment, and management of the health condition. The aldosterone test can be used to diagnose primary hyperaldosteronism and secondary hypoaldosteronism. In this test, a low response may indicate primary hyperaldosteronism of the adrenal glands, while a high response may indicate secondary hypoaldosteronism. The test is also prescribed to people undergoing treatment for hypertension to monitor the efficacy of the treatment plan.