Conn syndrome

Definition-What is Conn Syndrome?

Conn's syndrome, also known as primary aldosteronism, is caused by a pathological change in the adrenal cortex that leads to an overproduction of the messenger substance aldosterone. Aldosterone is a hormone that has an important function in regulating the human salt and water balance. Sometimes it plays a decisive role in the absorption of sodium and water and the release of potassium.

Causes of Conn's Syndrome

The cause of a Conn syndrome is a so-called in about 2/3 of the cases Hyperplasia. Hyperplasia describes an increase in the size of a tissue due to the multiplication of the cells located there.

The adrenal cortex is divided into zones that have different functions or produce different hormones. The part that is responsible for aldosterone production is called Zona glomerulosa. There are also two other zones in which mainly other hormones are produced. Hormone production is generally subject to complex control and feedback mechanisms in order to dose the amount of hormones in the body as required.

Conn syndrome occurs in the Zona glomerulosa to cell reproduction, as well as to disturbances in the regulatory mechanism. As a result, the cells produce large amounts of aldosterone unhindered.

Furthermore, a so-called Adenoma of the adrenal cortex lead to hyperaldosteronism. A Adenoma is a benign tumor that is composed of gland cells. In about 1/3 of the cases, such a change in the tissue is responsible for the increased production of aldosterone.


If Conn's syndrome is suspected, which usually arises from therapy-resistant high blood pressure, various diagnostic measures are used.

An important method is the determination of the aldosterone-renin quotient. Renin is another hormone that can affect blood pressure and is made in the kidney. If the blood pressure is too low, the kidneys release the hormone, which then naturally boosts aldosterone production in the adrenal cortex. If there is an increased amount of aldosterone or high blood pressure, the kidneys reduce their renin production and the concentration of renin in the blood is consequently reduced. The high blood pressure in Conn syndrome, which is caused by the high concentration of aldosterone, leads to such a drop in the renin content in the blood.
If you now consider the quotient of renin and aldosterone, this is increased in Conn's syndrome. A high renin-aldosterone quotient therefore suggests primary hyperaldosteronism.

Furthermore, the blood is checked for the concentration of potassium, which in this case is reduced. Before the blood test or to determine the values ​​of aldosterone, renin, etc., it is important to stop taking certain antihypertensive drugs, as these influence various messenger substances and can thus lead to falsified values.

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A saline stress test can also be carried out. If Conn's syndrome is suspected, the affected person is given a saline solution as an infusion. The salty liquid should normally lead to a reduction in aldosterone production in a healthy body. In the case of primary hyperaldosteronism, on the other hand, the aldosterone levels remain elevated.

Ultrasound, computed tomography or magnetic resonance tomography, or MRI for short, can be used as imaging methods. In particular, cell growths such as those that occur in the context of an adenoma can be shown well here.

I recognize Conn's syndrome by these symptoms

The main symptoms of Conn's syndrome are therapy-resistant high blood pressure and low potassium levels in the blood.

High blood pressure can lead to headaches and dizziness in those affected. Furthermore, sleep disorders, fatigue, nervousness and concentration disorders can show up in those affected.

From the low potassium content, a so-called Hypokalemia other symptoms may also arise. These include, among other things: a lack of drive and weakness, constipation, increased thirst and increased urination. Muscle weakness can also show up. Furthermore, it can lead to abnormal sensations on the skin, which on the disturbed ratio of electrolytes or also Minerals called, are due.

Weight gains

Weight gain is not a typical symptom of Conn's syndrome.

In the differential diagnosis, however, weight gain, especially in connection with high blood pressure, can indicate another disease of the adrenal cortex. This is what is known as Cushing's syndrome. A tumorous change in the adrenal gland itself or its controlling unit of the pituitary gland induces increased cortisol production. Weight gain is one of the typical symptoms of Cushing's syndrome.

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Fatigue can present itself as part of Conn's syndrome. However, this is a very unspecific syndrome whose presence alone has no disease value. In conjunction with blood pressure that is difficult to adjust, it can serve as an indication of a disorder of the adrenal gland, but often tiredness is not given too much attention among the symptoms of Conn's syndrome due to its non-specificity.

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Treatment / therapy

Therapy for Conn's syndrome depends on the cause. In the case of cell proliferation or hyperplasia of the adrenal cortex, certain drugs are usually used.

These include in particular spironalactone, a so-called Aldosterone antagonist. It is an antagonist of aldosterone, which blocks the docking sites with its active ingredient where aldosterone would normally develop its effect. The effect of the excess aldosterone and the associated potassium excretion and sodium and water absorption is thus interrupted.

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In the presence of a Adenoma, or a benign tissue growth, this is removed with a surgical procedure. Usually not only the adenoma but the entire adrenal gland is removed. The task of the removed adrenal gland can then be taken over by the remaining and above all healthy adrenal gland.

Read more on the topic: Postoperative Complications - What Are There?

Duration / forecast

Both the duration and the prognosis depend on the cause and the therapeutic measures.

The drugs that are used to treat Conn's syndrome do not cure the disease, but rather help to maintain natural function. In particular, the high blood pressure, which in the long term leads to damage to the blood vessels and hearts, is thus regulated and those affected have a much better prognosis of staying healthy longer.

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During surgery, Conn's syndrome can be cured by removing the adenoma. However, the decisive factor here is how long the body has been exposed to the stressful symptoms or whether changes in the cardiovascular system have already occurred in order to be able to make statements about the prognosis of those affected.

Course of disease

Adequate therapy will inhibit the influence of excess aldosterone and contain the symptoms and long-term damage that is primarily caused by high blood pressure.

If there is no treatment, it will have a negative impact on the cardiovascular system over time. A permanently high blood pressure leads to damage to the heart, the vessels in general and in particular the vessels of the eyes and kidneys. Treatment of Conn's syndrome is essential to prevent related diseases.

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Conn syndrome in the cat

Conn syndrome in cats is caused by a disorder or disease of the adrenal cortex. As with humans, there are basically two causes: An overproduction by aldosterone by one HyperplasiaThis means a cell proliferation of the tissue or a usually benign tumor, the so-called Adenoma.

The excess aldosterone also leads to therapy-resistant high blood pressure and reduced potassium levels in cats.

As therapeutic measures, surgical removal of the adrenal gland or drug treatment can be sought. In contrast to humans, surgery in cats is often associated with complications, so that the operation in the four-legged friends can unfortunately in some cases lead to the death of the cat. If there are no undesirable side effects from the surgery, the cats generally have a very good prognosis.

Drug therapy mainly consists of antihypertensive drugs. The prognosis through drug treatment cannot be predicted across the board, in the few cats whose survival time was measured there were strong fluctuations between nine months and a few years.

In contrast to humans, the success of therapy or a statement about the prognosis in cats is generally much more difficult.