Adrenal Disorders: Specialists & Information

The adrenal glands are important hormone-producing organs located on either side of the kidneys, on what are known as the upper poles of the kidneys. An adrenal gland is about the size of a tablespoon but has an extremely complex tissue and cellular architecture. The adrenal gland produces various hormones:

• Norepinephrine and epinephrine are produced in the adrenal medulla. In medical terms, these are also referred to as catecholamines, which are generally understood to be stress hormones.
• The adrenal cortex consists of three distinct layers of cells. These layers are responsible for producing important hormones, including:
  • Aldosterone (regulates water balance and blood pressure)
  • Testosterone (male sex hormone)
  • Cortisol (an important stress hormone)

The adrenal glands sit on top of the kidneys. They are divided into the adrenal medulla and the adrenal cortex © Henrie | AdobeStock

Various diseases can disrupt hormone production in the adrenal glands. Such a disruption can result in the production and release of too few or too many hormones. This is referred to as hypofunction or hyperfunction. Additionally, disorders are classified based on the location of the damage as either adrenal cortex disorders or adrenal medulla disorders. 

In summary, there are four distinct clinical presentations:

1. Hyperfunction of the adrenal cortex
2. Hypofunction of the adrenal cortex
3. Hyperfunction of the adrenal medulla
4. Hypofunction of the adrenal medulla

What are the symptoms of adrenal cortex hyperfunction?

Hyperfunction of the adrenal cortex can lead to an excess of the metabolic hormone cortisol (Cushing’s disease) or the water/electrolyte hormone aldosterone (Conn’s syndrome).

Patients with Cushing’s disease suffer from metabolic disturbances due to the overproduction of cortisol. This can lead to the following symptoms and problems:

• Weight gain
• Fat deposits in the neck or abdominal area
• Glucose metabolism changes, and
• the skin becomes thin and parchment-like.

In Conn’s syndrome, also known as hyperaldosteronism, excessive production of aldosterone leads to disturbances in fluid balance and muscle function. A key symptom is severe high blood pressure. In addition, potassium levels drop, which manifests as

• constipation,
• muscle weakness
• excessive thirst, and
• frequent urination

.

What are the symptoms of adrenal insufficiency?

If the adrenal gland does not produce enough cortisol, adrenal insufficiency develops. A distinction is made here between a primary and a secondary form.

The primary form is also known as Addison’s disease. In this case, the cause of the disease lies in the adrenal cortex. This condition leads to symptoms such as:

• fatigue and weakness,
• darkening of the skin (hyperpigmentation),
• Nausea and vomiting, and
• diarrhea.

Secondary adrenal insufficiency is often caused by disorders outside the adrenal cortex in upstream “control centers,” which include the pituitary gland and the hypothalamus (the region of the brain above it). 

The hypothalamus stimulates the pituitary gland with the hormone CRH (corticotropin-releasing hormone), whereupon the pituitary gland stimulates the adrenal gland with the hormone ACTH (adrenocorticotropic hormone). If either of these hormones is produced in insufficient quantities or not at all, secondary adrenal insufficiency results. Those affected experience the following symptoms:

• They usually feel lethargic and tired.
• They suffer from weight loss and loss of appetite, as well as
• low blood pressure.
• The skin, nail beds, and fresh scars become darker in color.
• In women, menstruation often stops as well.

In everyday life, those affected usually do not notice any symptoms. Symptoms typically only appear during periods of mental or physical stress, as the body then requires more cortisol. This can lead to a severe physical crisis, which is also known as an “Addisonian crisis” after the physician who first described it. Patients then typically suffer from

• vomiting,
• diarrhea,
• shock or a
• drop in blood pressure.

What symptoms occur with hyperfunction of the adrenal medulla?

When the adrenal medulla is overactive, increased levels of

• dopamine
• norepinephrine, or
• adrenaline

. Since these stress hormones remain persistently elevated, this leads to

• high blood pressure,
• cardiac arrhythmias, or
• an increased heart rate.

Patients are usually very pale and also suffer from dizziness and headaches. Since metabolism is significantly increased, blood sugar levels also rise. This creates a risk that those affected will develop diabetes mellitus.

How can you tell if you have adrenal insufficiency?

However, the production of stress hormones may also be reduced, leading to

• frequent dizziness,
• fainting,
• ringing in the ears
• headaches, or
• fluctuating blood pressure

.

The causes of primary adrenal insufficiency lie within the organ itself. Various conditions can be responsible for this, such as infectious diseases like tuberculosis. However, autoimmune diseases, in which the body destroys its own tissue, can also underlie adrenal insufficiency. Finally, tumors can also lead to the deterioration and destruction of adrenal tissue, particularly in the context of surgeries performed due to adrenal tumors. 

In cases of secondary insufficiency, the hypothalamus or pituitary gland may be affected due to

• a severe accident involving traumatic brain injury,
• a tumor,
• inflammation, or
• following radiation therapy

may not release sufficient amounts of ACTH or CRH. As a result, the adrenal cortex does not produce hormones and therefore remains inactive.

However, a tumor in the brain can also cause the hypothalamus or the pituitary gland to release too much CRH or ACTH. This is often the cause of excessive cortisol production.

In addition, a tumor—usually benign—can form in the adrenal cortex, which then autonomously produces cortisol. Without treatment, this overproduction leads to Cushing’s disease.

The causes of aldosterone overproduction are also found in the adrenal cortex. In most cases, secretory cells proliferate for unknown reasons, or a benign tumor triggers autonomous production. However, another cause may be increased secretion of CRH or ACTH by the hypothalamus or the pituitary gland.

Hyperfunction of the adrenal medulla is usually also attributable to a benign tumor that is hormonally active. If the production of stress hormones in the adrenal medulla is reduced, this is usually due to long-term alcohol consumption or diabetes. Both conditions damage the adrenal medulla.

However, production capacity can also be limited by a tumor that is not hormonally active.

Treatment is always preceded by a detailed medical history and subsequent laboratory testing. With the help of these tests, the specialist (endocrinologist or nephrologist) can determine

• what the blood concentrations of the respective hormones are and
• what their relative levels are.

In addition, the underlying causes of the specific condition can be identified. In addition to laboratory tests, further examinations such as

• MRI,
• CT scans, or
• ultrasound

may be required.

After diagnosis, doctors treat the underlying causes of the specific adrenal disorder. In cases of hormone deficiency, the patient is prescribed medications containing the appropriate active ingredients.

In cases of overproduction of certain hormones, addressing the underlying cause also plays a key role. In addition, adjunctive drug therapy is often necessary.

If hormones are produced by a tumor, it must be surgically removed.

The course of an adrenal disorder depends on how quickly tissue damage occurs in the adrenal cortex. Without appropriate treatment, the disease progresses, causing the body to grow increasingly weaker.

However, if treatment is initiated early and is adequate, patients can expect a good quality of life.