You might not have heard much about the adrenal glands before, but these small glands — weighing around a teaspoon of sugar each — produce a range of hormones that are essential to human life. This is why it's important to understand adrenal gland function and to know what to look for if these glands are not working as they should.
The adrenal glands (or suprarenal glands) are two small, triangular glands. There’s one adrenal gland on top of each kidney.
They are among our endocrine glands, part of the endocrine system that releases and monitors levels of hormones around the body. Adrenal gland function produces vital hormones that regulate our immune system, blood pressure, metabolism, stress response, and other key functions.
Our adrenal glands consist of two main sections: the cortex (outer part) and the medulla (inner part). The adrenal cortex is much larger than the medulla and is further subdivided into the zona glomerulosa, zona fasciculata, and zona reticularis.
Each part of the adrenal glands produces and releases different hormones. The main adrenal hormones can be categorized into catecholamines and steroids. Catecholamines are produced and released by the adrenal medulla, and the steroid hormones by the adrenal cortex.
These are the hormones involved in our body’s “fight or flight” response in response to physical or emotional stress. The two have similar functions and are able to carry out a number of functions, including increasing heart rate, blood flow to the muscles and brain, and blood sugar levels.
Norepinephrine helps to maintain blood pressure by controlling the squeezing of blood vessels in a process known as vasoconstriction. Epinephrine can relax the smooth muscles in the airways to improve breathing. All these functions are designed to help your body respond to a perceived danger.
Cortisol, also known as the "stress hormone," is essential to life. It regulates the body’s stress response and aids in the control of how our bodies use proteins, carbohydrates, and fats. It also keeps our blood pressure and blood sugar in check and suppresses inflammation in the short term. In addition, it controls the circadian rhythm (or sleep/wake cycle), with healthy levels being high in the morning and low in the evening. Your daily patterns of cortisol can be affected by lifestyle factors, like working night shifts, and by adrenal conditions.
In times of stress, the adrenal cortex prepares the body by releasing cortisol in response to the Hypothalamus-Pituitary-Adrenal Axis (HPA axis). This happens as a second-wave response to stress, just after the epinephrine released in the “fight or flight” response starts to level out.
The HPA axis works by the hypothalamus, a small structure in the lower middle of the brain, sending signals to the pituitary gland (using a hormone called corticotropin-releasing hormone, or CRH). The pituitary gland sits just below the hypothalamus in the brain. In response to CRH, it sends signals to the adrenal gland by releasing adrenocorticotropic hormone (ACTH) into the bloodstream. When the ACTH reaches the adrenal glands, it stimulates them to secrete cortisol. When enough cortisol has been made, signals are sent to the hypothalamus to turn the HPA axis off.
DHEA is a “prohormone” made in the adrenal glands, with levels peaking in early adulthood and gradually falling as we age. Different parts of the body use DHEA as a precursor to make many other hormones, including testosterone, estrogen, progesterone, and cortisol.
This hormone plays a major part in regulating blood pressure and electrolyte balance, such as sodium and potassium levels. Aldosterone causes the kidneys to retain more sodium in the body or to release more potassium into the urine to be excreted out of the body. When your body retains sodium, it also retains water. This increases blood volume and raises blood pressure.
Sometimes our adrenal glands might not work properly, resulting in too much or too little of one or more of the different hormones they produce. The effect of improper function depends on which part of the adrenal gland is affected and the condition causing the abnormal adrenal gland function. We look further into some of the most common conditions affecting the adrenal glands below.
There are many causes that can lead to issues with the adrenal glands. These include:
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There are a variety of conditions that can affect the adrenal glands, with different hormones being affected depending on where in the adrenal gland the condition has its effect. Here, we outline the most common of these conditions.
This rare disorder damages the adrenal glands so that they’re not able to produce enough aldosterone or cortisol. Symptoms include fatigue, muscle weakness, low mood, increased thirst, and unintentional weight loss. A sudden worsening of symptoms in someone with Addison's disease is known as an “adrenal crisis” and must be treated as a medical emergency.
This condition is caused by either an adenoma (non-cancerous tumor) or enlarged zona glomerulosa in the adrenal cortex, either of which lead to raised aldosterone from the adrenal glands. This leads to hard-to-treat hypertension — for example, a patient can be on three blood pressure medications and still have raised blood pressure. Blood tests may help reveal this condition by showing low potassium.
This is caused by too much cortisol in the body building up over time, often after long-term use of steroid medications containing synthetic cortisol or due to the adrenal glands making surplus cortisol, usually because of a tumor.
Cushing's disease is a particular type of Cushing’s syndrome caused by a pituitary tumor. Symptoms of Cushing’s syndrome include excess abdominal fat, large purple stretch marks, a “buffalo hump” protrusion of the neck and shoulders, and thinner arms and legs from muscle wastage.
This rare tumor causes an overproduction of epinephrine and norepinephrine from the adrenal glands. The tumors are usually found in the adrenal medulla, with nine in 10 being non-cancerous. Classical symptoms are episodes of headache, sweating, and heart palpitations. Some people may not experience any symptoms and the tumor is detected incidentally on MRI (magnetic resonance imaging), CT (computed tomography), or PET (positron emission tomography) scans — just one reason why regular proactive screenings are important for our health.
Adrenal cancer, also known as adrenocortical carcinoma, is a rare type of cancer originating in the adrenal cortex. Symptoms can include hormonal changes, unexplained weight loss or gain, fatigue, and high blood pressure.
This is a group of inherited conditions present from birth that involve the adrenal glands going through hyperplasia, meaning they're larger than usual, and functioning abnormally. It causes cortisol and/or aldosterone to be deficient to varying degrees and, in some cases, increases levels of androgens. If symptoms are severe, the condition is usually picked up soon after birth; otherwise, it's usually detected in childhood.
Symptoms of severe CAH include dehydration, being sick, and abnormal heart rhythm, and female babies being born with ambiguous or male-looking genitalia.
Two of the causes of this condition are congenital adrenal hyperplasia and Cushing’s syndrome, leading to thick, dark hair growing on the face, neck, abdomen, chest, lower back, thighs, or buttocks. This mainly affects people assigned female at birth. It can affect men, but it's more difficult to differentiate it from typical male body hair.
This condition is also caused by raised androgens and is defined as puberty starting before eight years of age in girls and nine years in boys.
The symptoms experienced are different depending on which part of the adrenal glands and which hormone production are affected.
Symptoms can include:
Some of these symptoms are quite non-specific and may be due to other causes. However, it’s important to see your healthcare provider if you're experiencing any of these symptoms.
The term "adrenal fatigue" is often used to refer to symptoms that are thought to be caused by chronic stress, such as fatigue, body aches, poor sleep, and digestive issues. However, there's no current scientific backing for "adrenal fatigue" and the condition is not medically recognized. That means it's likely that anyone suggesting a person has "adrenal fatigue" isn't a medical professional. Without a professional screening by a certified health care practitioner, someone experiencing these symptoms might miss their true diagnosis and relevant treatment.
Tests for conditions which affect the adrenal gland function include:
If you have any symptoms indicating a potential issue with your adrenal glands, a primary care physician should be able to order initial tests. You may be referred to an endocrinologist for more specialist testing.
An Ezra Full Body Scan may also detect several warning signs and help you and your health care provider stay on top of your adrenal gland function.
Treatment for adrenal issues depends on the cause of the change to your adrenal gland function. Options may include medications to alter hormone levels or reduce the effect of certain hormones on your body. In the case of a tumor, treatment may include surgery, radiotherapy, or chemotherapy.
A person can live without adrenal glands, but they would need lifelong treatment to replace the essential hormones that the adrenal glands can no longer produce. This usually results from a rare situation where someone has needed both adrenal glands to be surgically removed.
The adrenal glands provide a range of functions that are necessary to life. As there are various hormones they produce and release into the body, there are a variety of conditions that stem from changes to adrenal gland function. Many of the symptoms are quite generalized and occasionally there may be no symptoms, such as some cases of pheochromocytoma.
It’s important to be aware of what to look out for and to be proactive about your health. As part of keeping an eye on your health, consider booking an Ezra Full Body Scan. This innovative scan screens 13 organs, including the adrenal glands, to pick up any potential abnormalities. Regular scans may help with early detection, which is the best defense against serious conditions.
