4 Ways to Diagnose Hyperaldosteronism

1. What Makes a Doctor Initially Suspect Hyperaldosteronism?

Hyperaldosteronism results when one’s adrenal glands create elevated levels of the hormone aldosterone. Causes of hyperaldosteronism include a benign tumor in an adrenal gland (Conn’s syndrome) or enlarged adrenal glands. Elevated levels of aldosterone cause one’s body to have low potassium levels (hypokalemia) and elevated sodium levels. People with hyperaldosteronism also typically have high blood pressure that doesn’t respond to blood pressure lowering drugs. A doctor might initially suspect hyperaldosteronism if a patient presents with high blood pressure, a low level of potassium in their blood serum and an elevated serum sodium level. A doctor will also look for some of the other physical symptoms of hyperaldosteronism to help make the diagnosis. Some of these symptoms include muscle weakness, headache, fatigue, tingling, numbness and temporary paralysis.

2. Measure Aldosterone and Renin Levels

If a doctor suspects a case of hyperaldosteronism, the next step in making the diagnosis is to measure the levels of renin and aldosterone in the patient’s blood. Aldosterone is a hormone released by the adrenal glands, and renin is an enzyme produced in the kidneys. Renin helps to regulate one’s blood pressure. People with hyperaldosteronism will have elevated plasma aldosterone levels and decreased plasma renin levels. Because of the decreased amount of renin, patients with hyperaldosteronism typically have high blood pressure. Some doctors may also measure aldosterone levels in a patient’s urine to aid in the diagnosis of hyperaldosteronism.

3. Aldosterone Suppression Test

Another aspect of the diagnosis of hyperaldosteronism is performing an aldosterone suppression test. In this particular test, a doctor will increase a patient’s sodium levels to see how the patient’s aldosterone levels respond. Doctors can perform this test in several ways. They can have their patient eat a diet high in sodium for three days prior to the test or they can introduce salt water into the patient’s bloodstream for several hours prior to the test. In people without hyperaldosteronism, increasing their serum sodium levels will result in a decreased level of aldosterone in their blood (aldosterone suppression). However, patients with hyperaldosteronism will exhibit aldosterone levels that remain high despite the elevation in serum sodium levels.

4. Look for the Cause of Hyperaldosteronism

To further confirm the diagnosis of hyperaldosteronism, doctors will want to determine the cause of the condition. Doctors may use imaging techniques such as computerized tomography (CT) or magnetic resonance imaging (MRI) to look for a tumor on the adrenal gland. These imaging techniques can also help a doctor see if the adrenal glands appear enlarged, which can result in overactive adrenal glands and the overproduction of aldosterone. In addition, some doctors will use adrenal vein sampling to help understand the cause of hyperaldosteronism. In this test, a doctor will draw blood from the patient’s left and right adrenal veins and measure the levels of aldosterone in these samples. If the aldosterone levels appear elevated in both samples, then the patient may have overactive adrenal glands. If one blood sample has a marked elevated level of aldosterone, the adrenal gland on that side likely contains a benign tumor.