What are Adrenal Glands?
The adrenal glands are located on the top of the kidney on both sides of the body.
Adrenal glands are orange-colored organs located on top of both kidneys. They are triangular, not round, and about the size and shape of a fortune cookie. Adrenal glands secrete several types of hormones and thus are part of the endocrine system. We all have two adrenal glands, but we can live just fine with only one (in fact, most people can live normally with about a third of one adrenal gland). Adrenal glands usually do not cause problems, but they can develop tumors, some of which require surgery.
What Do Adrenal Glands Do?
Adrenal glands secrete several types of hormones (cortisol, aldosterone, adrenaline and others) that help maintain blood pressure, salt balance and blood sugar, and help in times of stress. Read more about adrenal gland function. Humans cannot live without adrenal hormones, so if both adrenal glands are removed completely (very rarely necessary), the patient needs to take replacement hormones for life. This is why we favor adrenal-sparing surgery when both glands are affected.
Are Adrenal Tumors Common?
Adrenal tumors are common, and they often cause problems. Autopsy studies have found adrenal lesions larger than 1 cm in about 6% of people. Similarly, "adrenal incidentalomas" (adrenal tumors, nodules or adenomas identified on scans performed for other reasons) are found on a few percent of abdominal CT or MRI scans in adults. Adrenal tumors become more common with age: the likelihood of detecting an unsuspected adrenal lesion on an abdominal CT scan is only about 0.2% in young adults, versus about 7% or more in individuals over 70 years of age. Because the Carling Adrenal Center is a high-volume center dedicated to adrenal tumors, we also see many children and young adults, but adrenal tumors are more common in middle-aged and older patients.The majority of adrenal tumors are benign adrenocortical adenomas that make no excess hormone and often do not require surgery. However, when these tumors are tested properly, a substantial minority (about one in five in a large study) make too much cortisol. This is called adrenal hypercortisolism (AHC), formerly called MACS (mild autonomous cortisol secretion) or subclinical Cushing syndrome, and it is the most common hormone problem found in adrenal incidentalomas. An experienced healthcare team is needed to determine who does and does not need an operation.
If you do need an operation, it may save your life. Removing a hormone-producing tumor may help you live longer and may lower your risk of high blood pressure (and of needing medications that make you feel sick and tired), diabetes, heart arrhythmia, heart attack, heart failure and stroke. Surgery is usually the best treatment if you have an adrenal tumor that is overproducing hormones (functioning adrenal tumors may overproduce cortisol, aldosterone, catecholamines (adrenaline-type hormones) or sex-steroid hormones), although some patients, for example those with mild primary aldosteronism or aldosterone excess from both glands, do well on medication. For malignant adrenal tumors (adrenocortical carcinoma (ACC), metastatic pheochromocytoma, and metastasis of another cancer to the adrenal), surgery offers the best chance of cure, and some patients are cured.
The key to successful adrenal surgery. The key to having you and your adrenal mass treated correctly is to obtain guidance from an experienced, thoughtful, and knowledgeable team. In brief, you (the patient) need to be aware that:
- The symptoms of adrenal hormone excess may be absent, subtle, atypical and/or masked by medications. You need hormone testing (blood and sometimes urine tests) to know if your adrenal tumor is making excess hormone.
- The hormone work-up of an adrenal tumor is easy to get wrong because many common medications interfere with the tests. It is best done by a team that does it every day. You and your doctor need to arrive at the correct diagnosis while avoiding unnecessary laboratory tests and expensive scans.
- Your adrenal tumor may have been found accidentally via a scan (ultrasound, CT, MRI, PET scans, etc) you were getting for some other reason. This is called an "adrenal incidentaloma”, meaning it was found incidentally, by surprise. This does not mean you (or your physician, radiologist, or endocrinologist) should ignore it. Every adrenal incidentaloma needs a thorough workup including measuring your adrenal hormones. You still may need surgery!
- Since surgery is the only treatment that can cure a hormone-producing adrenal tumor, it is worth spending time on research to find an experienced adrenal surgeon.The most important factor for a desirable outcome is your choice of adrenal surgeon.
How to Find the Best Adrenal Surgeon?
Unfortunately, the typical surgeon who performs adrenal surgery in the United States does about one adrenal operation per year. You read that correctly: one. More than 80% of adrenalectomies in the United States are performed by low-volume surgeons, yet outcomes are better with surgeons who do the operation regularly. You, or your loved one, depend on having an experienced surgeon for an optimal outcome.In the United States, a high-volume adrenal surgeon according to the scientific literature is usually regarded as a surgeon performing 6 or more adrenal operations (adrenalectomies) per year. This is akin to stating that you are an expert airline pilot if you fly an aircraft only 6 times a year. Dr. Carling performs up to 750 adrenal operations a year, more in a single week than many surgeons perform in several years. Read more about how to find the best adrenal surgeon.
Last updated October 2026.