Conns Syndrome: Symptoms, Types, Causes and Treatment

Conns syndrome, also known as primary hyperaldosteronism, is an underdiagnosed but significant cause of secondary hypertension. This article explores its symptoms, types, causes, and treatment options, synthesizing current medical evidence and clinical experience. Whether you are a patient, healthcare provider, or simply curious, this comprehensive guide will help you understand the essentials and nuances of Conns syndrome.

Symptoms of Conns Syndrome

Conns syndrome can manifest in various ways, but some hallmark symptoms stand out. Recognizing these early can be life-changing, as many cases remain undetected for years, leading to severe complications like stroke or heart failure. Below, you'll find a quick summary of the primary symptoms, followed by a deeper dive into their clinical importance and variability.

Symptom	Description	Typicality	Source(s)
Hypertension	High blood pressure, often severe or resistant to treatment	Classic	1, 2, 3, 5
Hypokalemia	Low blood potassium, can cause muscle weakness or cramps	Classic	1, 2, 3, 7
Metabolic Alkalosis	Elevated blood pH due to excess base	Common	2, 5
Fatigue/Weakness	General lack of energy, muscle fatigue	Common	2, 7
Headache	Often due to high blood pressure	Common	2
Polyuria/Polydipsia	Increased urination and thirst	Sometimes	7
Neurological Symptoms	Rare presentations (e.g., confusion, seizures)	Atypical	1, 3

Table 1: Key Symptoms

Classic Symptoms: Hypertension and Hypokalemia

Hypertension is the most consistent symptom of Conns syndrome. Often, it's severe and resistant to standard antihypertensive therapies, requiring multiple medications. Hypokalemia, or low serum potassium, is another hallmark. This can lead to muscle cramps, weakness, and even dangerous heart rhythms. Many patients are prescribed potassium supplements for years before the correct diagnosis is made 1, 2, 5.

Metabolic Alkalosis and Fatigue

The excess aldosterone in Conns syndrome causes the kidneys to excrete potassium and retain sodium, leading to metabolic alkalosis (increased blood pH). This chemical imbalance can further exacerbate muscle weakness and fatigue, which are common complaints 2.

Atypical and Neurological Presentations

Not every patient fits the classic profile. Some present with normal potassium levels (normokalemia) or even normal blood pressure (normotension). Rarely, neurological symptoms such as confusion or seizures can be the primary presentation, making diagnosis a challenge 1, 3.

Pediatric Considerations

Although rare in children, symptoms like polyuria (frequent urination), polydipsia (excessive thirst), and fatigue may raise suspicion for Conns syndrome, especially when combined with persistent hypertension and hypokalemia 7.

Types of Conns Syndrome

Understanding the types of Conns syndrome is crucial for both prognosis and treatment decisions. While the umbrella term “primary hyperaldosteronism” encompasses several related disorders, Conns syndrome specifically refers to certain forms.

Type	Brief Description	Prevalence	Source(s)
Aldosterone-Producing Adenoma (APA)	Benign tumor in adrenal gland causing excess aldosterone	Most common	1, 2, 5, 7
Bilateral Adrenal Hyperplasia (BAH)	Both adrenal glands enlarged, overproducing aldosterone	Common	1, 5
Adrenocortical Carcinoma	Malignant tumor producing aldosterone	Rare	4, 8
Familial Hyperaldosteronism	Genetic forms, often with early onset	Rare	6, 7

Table 2: Types of Conns Syndrome

Aldosterone-Producing Adenoma (APA)

APA is the classic and most common type of Conns syndrome. It involves a benign tumor in one adrenal gland, leading to excess aldosterone secretion. This type is often curable through surgery, especially when identified early 1, 2, 5, 7.

Bilateral Adrenal Hyperplasia (BAH)

In BAH, both adrenal glands are affected, leading to generalized overproduction of aldosterone. Unlike APA, BAH is rarely treated surgically and is managed with medication 1, 5.

Aldosterone-Producing Adrenocortical Carcinoma

A very rare but aggressive form, this involves a malignant tumor in the adrenal cortex. The clinical course is often ominous, with poor survival outcomes and a higher likelihood of metastasis at diagnosis 4, 8.

Familial Hyperaldosteronism

Some cases are genetic, presenting in childhood or adolescence. Familial forms can be caused by inherited mutations, such as those affecting the KCNJ5 gene, though these are relatively uncommon 6, 7.

Causes of Conns Syndrome

Delving into the causes of Conns syndrome reveals a fascinating interplay of genetics, adrenal pathology, and sometimes, unknown factors. Understanding the root cause is essential for determining the most effective treatment.

Cause	Underlying Mechanism	Frequency	Source(s)
Aldosterone-Producing Adenoma	Single benign tumor secreting aldosterone	Most common	1, 2, 5, 7
Bilateral Adrenal Hyperplasia	Overgrowth of adrenal tissue, both glands	Common	1, 5
Adrenocortical Carcinoma	Malignant tumor, uncontrolled aldosterone	Rare	4, 8
Genetic Mutations (e.g., KCNJ5)	Hereditary mutations causing excess aldosterone	Very rare	6, 7
Idiopathic	Unknown or mixed causes	Occasionally	1, 3

Table 3: Causes of Conns Syndrome

Tumor-Related Causes

The overwhelming majority of Conns syndrome cases are due to a single benign tumor (aldosterone-producing adenoma) in one adrenal gland. These tumors autonomously secrete aldosterone, leading to the classic symptoms 1, 2, 5, 7. Less commonly, a malignant tumor (adrenocortical carcinoma) may be responsible, especially in aggressive or rapidly progressing cases 4, 8.

Adrenal Hyperplasia

Bilateral adrenal hyperplasia involves the non-cancerous enlargement of both adrenal glands, resulting in excess aldosterone production. This form is more likely to be managed medically as it is not amenable to surgical cure 1, 5.

Genetic and Familial Causes

Advances in genetic testing have identified rare inherited mutations, such as those in the KCNJ5 gene, which can predispose individuals to Conns syndrome. While these are rare, they are particularly important in pediatric or familial cases 6, 7.

Idiopathic Cases and Mixed Etiology

In some patients, no clear cause is found, or a combination of factors may be at play. These idiopathic cases can present diagnostic challenges and may require more extensive evaluation 1, 3.

Treatment of Conns Syndrome

Treatment for Conns syndrome is highly effective in most cases, especially when the diagnosis is made early. The approach varies depending on the underlying type, ranging from surgery to lifelong medication.

Treatment	Indication	Expected Results	Source(s)
Surgical Removal (Adrenalectomy)	Unilateral adenoma or localized disease	Potential cure, improved blood pressure	5, 9, 10, 12
Medication (e.g., Spironolactone)	Bilateral hyperplasia or non-surgical cases	Control of hypertension and hypokalemia	2, 5, 11
Laparoscopic Adrenalectomy	Minimally invasive surgical option	Faster recovery, good outcomes	9, 10, 12
Supportive Care	Pre- and post-operative management	Reduce complications	11, 12

Table 4: Treatment Options

Surgical Treatment: Adrenalectomy

Surgical removal of the affected adrenal gland is the first-line treatment for unilateral adenoma (APA). Laparoscopic adrenalectomy has become the gold standard, offering shorter hospital stays, quick recovery, and high rates of symptom improvement 5, 9, 10, 12. Most patients see normalization of potassium levels and often a significant reduction in blood pressure medications post-surgery. However, complete remission of hypertension is not guaranteed for all patients, especially older individuals or those with long-standing hypertension 12.

Surgical Outcomes

• Over 85% of patients report improved blood pressure control after surgery 9, 10.
• Many can reduce, or even stop, antihypertensive medications.
• Surgical complications are rare, and mortality is low when performed laparoscopically 5, 12.

Medical Management

For bilateral adrenal hyperplasia or inoperable cases, medical therapy is the mainstay. Mineralocorticoid receptor antagonists such as spironolactone or eplerenone are used to block the effects of aldosterone, thereby controlling blood pressure and correcting hypokalemia 2, 5, 11.

• Medication is also used pre-operatively to stabilize potassium and blood pressure.
• Lifelong therapy may be needed in some cases.

Pediatric and Rare Cases

Children with APA or familial forms typically undergo surgery, with reported cures in most cases 7. Malignant tumors may require more aggressive treatment, but prognosis is generally poor 4, 8.

Supportive and Perioperative Care

• Careful management before, during, and after surgery is vital to prevent complications such as blood pressure spikes or electrolyte imbalances 11.
• Ongoing follow-up is necessary to monitor for recurrence or persistence of symptoms 12.

Conclusion

Conns syndrome is a frequently overlooked yet treatable cause of secondary hypertension. Early recognition and targeted therapy can dramatically improve patient outcomes. Here’s a summary of the key points covered:

• Symptoms: Classic triad of hypertension, hypokalemia, and metabolic alkalosis, but presentations can vary.
• Types: Most cases are due to aldosterone-producing adenoma or bilateral adrenal hyperplasia; rare forms include carcinoma and familial types.
• Causes: Ranges from benign tumors to genetic mutations, with most cases involving a single adrenal adenoma.
• Treatment: Surgery offers potential cure for unilateral adenoma; medication is effective for bilateral hyperplasia and other forms; laparoscopic approaches provide excellent outcomes.

Key Takeaways:

• Early diagnosis is critical for best outcomes.
• Not all patients will be cured of hypertension, but most will see substantial improvement.
• Lifelong follow-up and management are essential, especially in complex or atypical cases.

If you or someone you know has resistant hypertension, persistent hypokalemia, or unexplained fatigue, consider discussing Conns syndrome with a healthcare professional. Prompt investigation and tailored treatment can be life-changing.