What is Conn's Syndrome?

Anatomy of the Adrenal Glands
Anatomy of the Adrenal Glands
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Conn's syndrome is a rare health problem that occurs when the adrenal glands make too much aldosterone. This problem is also known as primary hyperaldosteronism. Aldosterone is a hormone that controls salt and potassium levels in the blood. Too much leads to high blood pressure.

Only 1 out of 100 or fewer of all cases of high blood pressure are caused by Conn's syndrome. It is more common in females than in males. It can happen at any age, but more often in people in their 30s and 40s.

What Happens Under Normal Conditions?

The adrenal glands are found above each kidney. They are triangle-shaped, and measure about half an inch in height and 3 inches in length. Each adrenal gland has 2 layers.

  • The adrenal medulla (inner part) makes epinephrine (also called adrenaline).
  • The adrenal cortex (outer part) makes steroid hormones (such as cortisone and aldosterone).

Adrenal glands

The adrenal glands control many processes in the body. Their job is to keep the body in balance by making various hormones that are critical for maintaining good health.

These hormones do many important things. For example, they help regulate fluid and salt levels in the body that affect blood volume and blood pressure. They also help the body react to stress and change. They cause a faster heart rate and boost other systems that help you to react quickly with a burst of energy when needed. Problems in the cortex or the medulla, then, can result in high blood pressure.



What are the Symptoms of Conn’s Syndrome?

Most often, patients have higher than normal blood pressure. Blood tests help to tell if high blood pressure is from Conn’s Syndrome or something else. The usual treatment for high blood pressure doesn’t generally help treat hyperaldosteronism.

The abnormal electrolyte levels often seen with too much aldosterone lead to signs such as:

  • Lack of muscle strength
  • Frequent voiding
  • Nighttime voiding
  • Headache
  • Increased thirst
  • Pins and needles feeling
  • Eyesight problems
  • Paralysis that comes and goes
  • Muscle twitching and cramps

The severity may depend on the degree of the electrolyte abnormality.



What are the Causes of Conn’s Syndrome?

Most cases are random but some are passed down from a parent. Conn’s Syndrome could be due to a tumor on the adrenal gland (a benign cortical adenoma). It may be caused by an odd growth in both adrenal glands (known as a bilateral adrenal hyperplasia). Both health problems cause too much aldosterone to be released.

Sometimes excess aldosterone is caused by another health issue that lowers blood flow to the kidney. For example:

  • Fluid loss
  • Kidney artery narrowing
  • Heart failure
  • Shock
  • Liver disease
  • Pregnancy
  • Some kidney tumors

These cases are called "secondary hyperaldosteronism." This term is used because the excess hormone is not from a problem with the adrenal gland.



How is Conn’s Syndrome Diagnosed?

Blood and urine tests can check for high aldosterone and other blood levels. Your health care provider may order a CT scan or MRI to find the side of an adenoma or hyperplasia. Patients who have adrenal masses only need to be screened for Conn’s syndrome if they are known to have blood pressure issues. If patients with an adrenal mass are found to have a special test known as adrenal vein sampling is mandatory before the adrenal gland with the mass is removed, since in up to one third of patients the problem can stem from both or the opposite adrenal gland.



How is Conn’s Syndrome Treated?

Depending on the type of Conn's Syndrome you have the treatment may vary. Below are the common treatments.

Primary hyperaldosteronism caused by a tumor is most often treated by removing the adrenal gland (unilateral adrenalectomy). Remember that adrenal vein sampling is mandatory before the adrenal gland with the mass is removed, since in up to one third of patients the problem can stem from both or the opposite adrenal gland. This surgery is almost always done laparoscopically.

  • Bilateral hyperplasia is treated with diuretics (water pills), which help manage fluid buildup in the body.
  • Secondary hyperaldosteronism is most often treated with drugs.

It's important to know that adrenal surgery is complex. It helps to choose a surgeon who has significant experience with surgery in the area around the kidneys and adrenal glands. Talk with a few surgeons before you choose one to work with.



What Can Be Expected after Treatment?

Most patients have a rapid and uneventful recovery from surgery. High blood pressure is greatly improved in 80 out of 100 to 90 out of 100 of cases. But even after surgery, you may still have high blood pressure. You may need drugs for hours or weeks until your blood pressure returns to normal. The reason for this is not fully understood. It may be the result of kidney damage from primary hyperaldosteronism.

You should continue to see your health care provider after treatment so they can monitor you blood pressure and electrolytes levels.