Adrenal Glands: What to Know

Medically Reviewed by Jabeen Begum, MD on October 06, 2022
5 min read

Your body is made up of many different systems working together. One of those is the endocrine system, the system in your body that is responsible for hormone production and release. The adrenal glands are an essential part of this system.

Your adrenal glands are a pair of small, triangular glands that act as a part of your endocrine system. The endocrine system is a network of glands and organs within your body that make and release hormones. Hormones are chemicals that initiate and sustain functions all over your body. 

Aside from the adrenal glands, the endocrine system also includes the:

  • Hypothalamus. The hypothalamus is located within the brain and controls the endocrine system.
  • Ovaries. Ovaries are typically found in those assigned female at birth. The two ovaries release estrogen, progesterone, and testosterone. 
  • Pancreas. The pancreas makes insulin, which controls your blood sugar levels. 
  • Parathyroid. Your body has four parathyroid glands, and they’re tiny, roughly the size of grains of rice. They control how much calcium is in your body.
  • Pineal gland. The pineal gland is located within the brain. It controls your sleep cycle by releasing melatonin.
  • Pituitary gland. The pituitary gland is a small, pea-sized gland at the base of your brain. It makes several hormones that your body needs.
  • Testes. Testes are typically found in those assigned male at birth. Their job is to release testosterone, as well as to make sperm.
  • Thyroid. The butterfly-shaped thyroid gland is located at the front of your neck. It controls your metabolism. 

Where Are the Adrenal Glands Located?

You have two adrenal glands. One sits on top of each of your kidneys like little triangular hats. From this position, your adrenal glands receive instructions, then produce and release hormones.

The adrenal glands, like other parts of the endocrine system, make and release hormones. The adrenal glands’ hormones can be divided into two groups: catecholamines and steroid hormones.

Catecholamines. Catecholamines are the hormones that your body releases when you’re in a stressful situation. These hormones are made by the inner part of your adrenal glands, which are called the adrenal medulla. 

The catecholamines that your adrenal medulla release include:

  • Adrenaline. Also called epinephrine, the hormone adrenaline activates your body’s “fight or flight” response. When your brain senses danger, it produces adrenaline that encourages your body to make changes like dilating your pupils, increasing your blood flow, and breathing faster. Adrenaline also has many uses in medicine. It can be used to open the airways of asthma patients or those who are having an allergic reaction.
  • Noradrenaline. Also called norepinephrine, noradrenaline works alongside adrenaline to activate the fight or flight response. Its primary job is to increase and manage blood pressure. Noradrenaline also has several uses as a medication. It’s used to elevate blood pressure in the short term or in emergency situations. These situations may include overdoses, blood transfusions, septic shock, and heart attacks. 

Steroid hormones. Steroid hormones play a part in many bodily functions, including the immune response, metabolism, the balance of salt and water within your body, and the development of sex characteristics. These hormones are made in the outer part of the adrenal glands, which is called the adrenal cortex. 

The steroid hormones that the adrenal cortex makes include:

  • Aldosterone. The job of aldosterone in the body is to regulate your blood pressure and levels of the electrolytes potassium and sodium in your blood. As a result, aldosterone helps regulate your blood’s pH. Aldosterone is made in a section of the adrenal cortex called the zona glomerulosa.
  • Cortisol. The hormone cortisol has many jobs and affects many different systems of your body. It plays a role in controlling your sleep-wake cycle, controlling metabolism, regulating blood pressure and blood sugar levels, and reducing inflammation. Cortisol is sometimes called the “stress hormone” because it activates when you’re feeling stress to help your body manage that stress. Cortisol is made in the section of the adrenal cortex called the zona fasciculata. 
  • Dehydroepiandrosterone (DHEA). DHEA helps produce some sex hormones. It is sent to the ovaries, where it forms estrogen, or the testes, where it forms androgen. DHEA is produced in the zona reticularis area of the adrenal cortex.   

Many different conditions can affect your adrenal gland and the way it works.

Adrenal cancer. Sometimes, cancerous tumors may grow on the adrenal glands. Because this type of cancer is so rare, it often spreads to other organs before it’s diagnosed. Symptoms may include an excess of one or more adrenal hormones and abdominal pain.

Adrenal insufficiency. Adrenal insufficiency is a condition in which your adrenal glands don’t make enough cortisol. Primary adrenal insufficiency, also called Addison’s disease, occurs when something like an autoimmune disorder, cancer, or infection damages the adrenal gland. 

Secondary adrenal insufficiency is caused by a lack of the hormone adrenocorticotropin (ACTH). ACTH is the hormone your pituitary gland sends to your adrenal glands to tell them to produce more cortisol. It can be caused by long-term use of certain steroids or damage to the pituitary gland. Pituitary damage may be caused by tumors, radiation, loss of blood flow, or removal.

Adrenal insufficiency can have a wide variety of symptoms, including:

  • Dehydration
  • Diarrhea and vomiting
  • Dizziness
  • Fatigue
  • Irregular or missing menstrual periods
  • Loss of appetite
  • Low blood pressure
  • Low blood sugar
  • Muscle aches
  • Weakness

Severe or untreated adrenal insufficiency may lead to kidney failure and shock.

Congenital adrenal hyperplasia. Congenital adrenal hyperplasia is a genetic condition that results in adrenal insufficiency. It is caused by a lack of the enzyme that makes cortisol or the enzyme that makes aldosterone. Patients with congenital adrenal hyperplasia often have excess androgen, leading to early puberty in boys and more male characteristics in girls. 

Cushing Syndrome. Cushing syndrome happens when your adrenal glands produce too much cortisol. This can happen because of long-term use of some steroids but can also be caused by a tumor that causes the pituitary gland to release too much ACTH. Symptoms can include diabetes, fatigue, fatty deposits throughout the body, high blood pressure, muscle weakness, and weight gain. 

Hyperaldosteronism. Hyperaldosteronism happens when the adrenal glands produce too much aldosterone. Primary hyperaldosteronism is caused by an issue with the adrenal glands, such as a tumor, while secondary hyperaldosteronism is due to a medical condition elsewhere in the body. Symptoms include fatigue, headache, high blood pressure, low potassium, muscle weakness, and numbness. 

Overactive adrenal glands. Sometimes, the adrenal glands grow nodules. They may be cancerous or benign and may also lead to overproduction of one of the adrenal hormones. Symptoms will depend on what part of the adrenal gland is affected.

Pheochromocytoma. Pheochromocytoma is a tumor in the adrenal medulla that causes an excess of adrenaline or noradrenaline. Symptoms include anxiety, headaches, high blood pressure, rapid heart rate, sweating, and tremors.