Adrenal glands: Functions and related disorders
The adrenal glands are small glands that sit above the kidneys. The hormones they produce affect metabolism, blood sugar regulation, blood pressure, and many other essential functions.
A range of medical conditions can affect the adrenal glands. These include Addison’s disease, Cushing’s syndrome, and adrenal cancer, as well as high blood pressure due to the overproduction of aldosterone.
Read on to learn more about the functions of the adrenal glands and some of the conditions that affect them. We also discuss the causes, diagnoses, and treatment options related to adrenal gland disorders.
The adrenal glands have two parts: the cortex and the medulla.
The cortex is the outer part of the gland. It produces the hormones cortisol and aldosterone. The medulla, meanwhile, is the inner part of the gland. It produces the hormones adrenaline and noradrenaline.
These four hormones are essential to normal functioning in the body. They control many important functions, including:
- blood sugar levels
- blood pressure
- salt and water balance
- sexual development before and during puberty
- stress response
- the balance of sex hormones, including estrogen and testosterone
Sometimes, the adrenal glands produce too much or not enough of their hormones. When this happens, it is known as an adrenal gland disorder.
The following sections discuss the most common adrenal gland disorders.
Adrenal insufficiency and Addison’s disease
When the adrenal glands do not make enough cortisol, it is known as adrenal insufficiency. There are three types of adrenal insufficiency:
- Primary adrenal insufficiency, or Addison’s disease. This condition develops when the adrenal gland itself does not function well and cannot make enough cortisol.
- Secondary adrenal insufficiency. This occurs when the pituitary gland does not make enough of a hormone called adrenocorticotropin (ACTH). Without ACTH, the adrenals do not receive a signal to make cortisol.
- Tertiary adrenal insufficiency. This occurs when the brain cannot produce enough corticotropin-releasing hormone (CRH). Without CRH, the pituitary gland cannot make ACTH. This means that the adrenals cannot make enough cortisol.
There are many potential causes of adrenal insufficiency, including:
- autoimmune disease, which is the most common cause of Addison’s disease, according to the National Institute of Diabetes and Digestive and Kidney Diseases
- being born with damaged adrenal glands
- tumors on the adrenal glands or those that communicate with the adrenal glands
- infections, such as tuberculosis
- taking corticosteroids for a long time and then suddenly stopping
- having a condition that weakens the immune system, such as HIV or AIDS
- cancer in the adrenal glands
- traumatic brain injury
People with Addison’s disease will often have a deficiency in aldosterone as well as cortisol.
The symptoms of adrenal insufficiency can be difficult to spot. They may come on slowly, so a person may think that something else is causing them.
The most common signs and symptoms include:
- always feeling tired or weak
- unexplained weight loss
- loss of appetite
- nausea or vomiting
- dizziness or fainting when standing up
- low blood pressure
- low blood glucose
- irregular or absent menstrual periods before menopause
- cravings for salt or salty foods
- joint pain
- darkening of the skin, especially on scars, lips, skin folds, and joints
Adrenal insufficiency requires treatment. Without enough cortisol, a person may experience an adrenal crisis. Signs and symptoms of an adrenal crisis include:
If a person shows any signs of an adrenal crisis, they should seek immediate medical help. Without treatment, an adrenal crisis can be fatal.
Adrenal cancer is rare, affecting as few as 200 people in the United States each year, according to the American Cancer Society (ACS) . Benign, or noncancerous, tumors are much more common.
There are several types of adrenal tumor, including:
- Adenomas. Most tumors that affect the adrenal cortex are adenomas. These are benign tumors of the adrenal cortex. However, a doctor may need to remove them if they interfere with adrenal gland function or reach a certain size.
- Adrenocortical carcinoma. Although rare, this cancer can affect the cortex, which is the outer part of the adrenal gland.
- Neuroblastoma. This cancer occurs in childhood and may begin in the medulla, which is the inner part of the adrenal gland.
- Pheochromocytoma. This is a neuroendocrine tumor that affects the medulla. It results in high levels of adrenaline. Being diagnosed with this type of tumor requires genetic testing and at least yearly follow up because of its potential to become cancerous or to recur.
The ACS say that most tumors in the adrenals do not start there. Instead, they often arise because other cancers, such as breast cancer or lung cancer, spread to the adrenals.
Some signs and symptoms of adrenal cancer include:
- unexplained weight gain or loss
- high blood pressure
- high blood sugar or diabetes
- low blood potassium
- anxiety, nervousness, or panic attacks
- heart palpitations
- excessive sweating
- abdominal pain
- unusual hair growth
- an increase in acne
- changes to genitals or sex drive
People with Cushing’s syndrome have adrenals that produce too much cortisol. The most common cause of this is using medications called glucocorticoids for a long time and at high dosages.
Glucocorticoids help treat many conditions, including asthma, rheumatoid arthritis, and lupus. They act like cortisol in the body.
Certain tumors can also cause Cushing’s syndrome. These include:
- Pituitary adenomas. These are benign growths on the pituitary gland. They can make the pituitary gland produce too much ACTH, which results in too much cortisol.
- Ectopic ACTH-producing tumors. These produce too much ACTH but are not located on the pituitary gland. Instead, they may be located on the lungs, pancreas, thyroid, or other areas.
- Adenomas or other adrenal tumors.
Some signs and symptoms of Cushing’s syndrome include:
- fat buildup around the base of the neck
- a fatty hump between the shoulders
- a round face
- unexplained weight gain
- thin arms and legs
- skin that bruises easily
- wide, purple stretch marks on the abdomen, hips, and breasts
- excess hair on the face, neck, chest, abdomen, and thighs (in females)
- irregular or absent menstrual periods (in females)
- low fertility, low libido, or erectile dysfunction (in males)
- obesity and slow growth (in children)
Congenital adrenal hyperplasia
A person inherits congenital adrenal hyperplasia (CAH) because of a genetic variation. This means that they will have it at birth. However, the symptoms may not be obvious straight away.
When a person has CAH, they do not have enough enzymes to make the hormone cortisol. As a result, they may have very little cortisol or none at all. Many people with CAH also have low levels of aldosterone.
Classic CAH is the more severe type. Doctors often diagnose it at birth or during infancy. An infant with classic CAH may have enlarged genitals. They may also have other symptoms, such as vomiting or weight loss.
If the infant does not receive treatment, classic CAH can lead to shock, coma, or death.
Nonclassic CAH is a mild condition that is not life threatening. Most of the time, the symptoms are not obvious until the infant reaches childhood or adulthood.
Some later signs and symptoms may include:
- rapid growth during childhood
- early acne, pubic hair, or armpit hair
- facial hair, acne, or a deep voice (in females)