Primary aldosteronism

Primary aldosteronism (PA), also known as primary hyperaldosteronism, is the excess production of the hormone aldosterone from the adrenal glands, resulting in low renin levels and high blood pressure. This abnormality is a paraneoplastic syndrome (i.e. caused by hyperplasia or tumors). About 35% of the cases are caused by a single aldosterone-secreting adenoma, a condition known as Conn's syndrome. Many patients experience fatigue, potassium deficiency and high blood pressure which may cause poor vision, confusion or headaches. Symptoms may also include: muscular aches and weakness, muscle spasms, low back and flank pain from the kidneys, trembling, tingling sensations, dizziness/vertigo, nocturia and excessive urination. Complications include cardiovascular disease such as stroke, myocardial infarction, kidney failure and abnormal heart rhythms. Primary hyperaldosteronism has a number of causes. About 33% of cases are due to an adrenal adenoma that produces aldosterone, and 66% of cases are due to an enlargement of both adrenal glands. Other uncommon causes include adrenal cancer and an inherited disorder called familial hyperaldosteronism. PA is underdiagnosed; the Endocrine Society recommends screening people with high blood pressure who are at increased risk, while others recommend screening all people with high blood pressure for the disease. Screening is usually done by measuring the aldosterone-to-renin ratio in the blood (ARR) whilst off interfering medications and a serum potassium over 4, with further testing used to confirm positive results. While low blood potassium is classically described in primary hyperaldosteronism, this is only present in about a quarter of people. To determine the underlying cause, medical imaging is carried out. Some cases may be cured by removing the adenoma by surgery after localization with adrenal venous sampling (AVS). A single adrenal gland may also be removed in cases where only one is enlarged. In cases due to enlargement of both glands, treatment is typically...