A pheochromocytoma is an infrequent tumor that typically has a non-malignant nature, and it arises within one of the adrenal glands situated on top of each kidney. The adrenal glands are a crucial component of the body’s endocrine system, responsible for producing various hormones.

A pheochromocytoma often only affects one adrenal gland. However, it can form in both glands.

The inner layer of the adrenal gland, known as the adrenal medulla, is where 80–85% most pheochromocytomas develop. The term extra-adrenal pheochromocytomas or paragangliomas refers to the 15-20% of pheochromocytomas that develop outside of this region.

If an individual has a pheochromocytoma, the tumor can discharge hormones that may cause panic attack-like symptoms, elevated blood pressure, headaches, and sweating. If left untreated, the pheochromocytoma can lead to severe or even life-threatening damage to other bodily systems.

Blood pressure typically returns to normal after a pheochromocytoma has been surgically removed.


Pheochromocytoma symptoms and signs frequently include:

  • Elevated blood pressure
  • Headache
  • Profused sweating
  • Tremor
  • Increased heart rate
  • Being pale
  • Difficulty of breathing
  • Symptoms similar to a panic attack

Less frequent signs or symptoms could be:

  • Losing weight
  • Anxiousness or fear of something terrible is going to happen
  • Constipation
  • Blurred vision

Symptomatic spells

Pheochromocytoma symptoms can be persistent, sporadic, or both, and they can also worsen. Activities, environmental factors, meals heavy in tyramine, a compound that influences blood pressure, and drugs can all trigger these episodes.

The following situations or behaviors can exacerbate symptoms:

  • Strenuous physical activity
  • Anxiety
  • Stress
  • Changing one’s physical position, such as standing up after lying down or sitting
  • Labor and giving birth
  • Having surgery and using anesthesia, a medicine that puts you to sleep during the procedure

Tyramine, a chemical that influences blood pressure, is present in foods and can exacerbate symptoms. Foods that have been fermented, aged, pickled, cured, overripe, or spoilt frequently contain tyramine. Examples of these foods are beers, wines, chocolates, smoked or dried meats, and certain types of cheese.

There are some drugs that can elevate the symptoms, including Monoamine Oxidase Inhibitors (MAOIs) (e.g., phenelzine, tranylcypromine and isocarboxazid), and stimulants (e.g., amphetamines and cocaine).

Despite the fact that a pheochromocytoma’s major symptom is elevated blood pressure, most persons with this condition do not also have an adrenal tumor. If any of the following apply to you, speak with your health care provider:

  • A history of pheochromocytoma in the family
  • A history of a related genetic ailment in the family, such as neurofibromatosis type 1, von Hippel-Lindau disease, hereditary paraganglioma syndromes, or multiple endocrine neoplasia, type 2 (MEN 2).
  • High blood pressure that is difficult to manage with existing therapies
  • Periods in which high blood pressure worsens


The specific causes of pheochromocytomas remain unknown, as per researchers. These tumors develop in the chromaffin cells, specialized cells present in the center of the adrenal gland. The primary hormones released by these cells are adrenaline (epinephrine) and noradrenaline (norepinephrine), which regulate several bodily processes like heart rate, blood pressure, and blood sugar levels.

In response to a perceived threat, adrenaline and noradrenaline trigger the body’s fight-or-flight response, causing an increased heart rate and elevated blood pressure, preparing the body for a quick reaction. However, a pheochromocytoma releases excessive amounts of these hormones, even when there is no danger, leading to symptoms.

Adrenal glands contain the majority of the chromaffin cells. However, there are also minor groups of these cells in the heart, head, neck, bladder, back wall of the stomach, and throughout the spine. Paragangliomas are chromaffin cell tumors that develop outside of the adrenal glands. They may have the same impact on the body to a pheochromocytoma.

Risk factors

The majority of pheochromocytomas are found in patients between the ages of 20 and 50. However, a tumor can appear at any age.

Pheochromocytoma or paraganglioma risk is higher in people with some rare hereditary diseases. These conditions increase the likelihood that a tumor will be malignant. Both of the adrenal glands are also more prone to developing tumors. These inherited conditions consist of:

  • Multiple endocrine neoplasia, type 2 (MEN 2) is a condition that causes tumors in multiple endocrine system organs. Both type 2A and type 2B are categories of multiple endocrine neoplasia (MEN) disorders that are associated with the development of pheochromocytomas. The thyroid, parathyroid, lips, tongue, digestive system, and other bodily regions may also develop tumors related with this illness.
  • Von Hippel-Lindau disease may lead to tumors at a variety of locations, including the kidneys, pancreas, endocrine system, and central nervous system.
  • Neurofibromatosis 1 generates a lot of skin tumors (neurofibromas), pigmented skin spots, and tumors of the optic nerve.
  • Hereditary paraganglioma syndromes are hereditary diseases that can cause paragangliomas or pheochromocytomas.