Adrenal Adenoma: What Symptoms It Causes and When It Is Harmless

What symptoms does an adrenal adenoma cause?

Usually none, if the adenoma is small and nonfunctioning. Most adrenal masses found by chance are nonfunctioning adenomas^[1]. A small nonfunctioning adenoma usually does not hurt and does not affect how you feel. A large mass can press on nearby organs and cause pain or a feeling of pressure in the side.

Typical symptoms appear mainly when the tumor produces hormones in excess. The adrenal gland makes several hormones, and an excess of each one gives its own picture:

• aldosterone: high blood pressure, sometimes muscle weakness and cramps due to low potassium;
• cortisol: weight gain around the abdomen and face, diabetes, high blood pressure, fragile bones;
• adrenaline and noradrenaline: attacks of palpitations, sweating and headache. These are produced not by an adenoma but by a different adrenal tumor, a pheochromocytoma, which can look similar on a scan.

The types of adrenal tumors and how they are investigated are described on the adrenal tumors page.

Adrenal adenoma and blood pressure: when to suspect excess aldosterone

When blood pressure is high and hard to treat, especially at a young age or together with low potassium. These signs are a reason to check for primary aldosteronism, that is, excess aldosterone. Its source can be an adenoma in one adrenal gland or both adrenal glands. Aldosterone makes the body retain sodium and water and lose potassium, so blood pressure is often hard to bring down, and low potassium can show up as muscle weakness and cramps.

There is no point waiting for low potassium or any particular sensation. The 2025 Endocrine Society guideline suggests screening everyone with high blood pressure for primary aldosteronism, with a blood test for aldosterone and renin and their ratio^[2]. The guideline authors stress that primary aldosteronism is a common cause of hypertension that is still rarely diagnosed, and that it carries a higher risk of cardiovascular complications than ordinary hypertension^[2].

The adenoma seen on a scan is not always the source of the hormone. So, to find out which side it is, blood is usually sampled from the veins of both adrenal glands in addition to CT^[2]. If the excess comes from one adrenal gland and the person is able and willing to have surgery, removal of that gland is offered, most often laparoscopically^[6]. If not, medication that blocks the action of aldosterone is prescribed^[2].

Excess cortisol: from Cushing’s syndrome to the hidden form

Overt cortisol excess is often visible; mild excess is found by tests. In Cushing’s syndrome, weight builds up mainly around the abdomen, face, neck and above the collarbones. The four features that best tell it apart from ordinary weight gain are bruising without an obvious knock, a red face, weakness in the thigh and shoulder muscles (difficulty getting up from a low chair or climbing stairs) and reddish-purple stretch marks more than 1 cm wide^[3]. There may also be high blood pressure, type 2 diabetes, vertebral osteoporosis, depression, and problems with sleep and memory^[3]. None of these features proves the diagnosis on its own.

It can also be different: the adenoma makes extra cortisol, but there are no overt signs of Cushing’s. This form is called mild autonomous cortisol secretion. It is looked for with a 1 mg dexamethasone suppression test: the person takes a tablet late in the evening and has a blood test for cortisol the next morning. A result above 50 nmol/L is considered abnormal^[1], but on its own it is not yet a diagnosis: an endocrinologist rules out other causes, repeats the test and checks the ACTH level^[1].

This kind of excess may show no outward signs, but research links it to a higher risk of illness and death^[1]. So these patients are checked separately for high blood pressure and type 2 diabetes, and these are treated. If such complications are already present, surgery is discussed on an individual basis^[1].

Attacks of palpitations, sweating and headache

Attacks like these are typical not of an adenoma but of a pheochromocytoma, a tumor of the adrenal medulla that releases adrenaline and/or noradrenaline. During an attack, palpitations, headache, sweating, pallor and trembling come on suddenly, and blood pressure jumps. An attack can start on its own or after physical exertion, pressure on the abdomen, a large meal, alcohol, stress or certain medications, including glucocorticoids^[4].

Not everyone has the classic symptoms. In a pooled analysis of studies, headache occurred in 60% of patients with pheochromocytoma, palpitations in 59% and sweating in 52%^[4]. And in two patient series, nearly two thirds of pheochromocytomas were found by chance, on scans done for another reason^[4].

That is why, if an adrenal mass does not have the typical features of an adenoma on CT, metanephrines in blood or urine are checked, even when there are no attacks^[1][5]. And before surgery for a pheochromocytoma, preparation is given, mainly alpha-blockers, to reduce the risk of sharp swings in blood pressure during the operation^[5].

A very severe headache, chest pain, shortness of breath, or sudden problems with vision or speech are a reason to call an ambulance on 103, whether or not you know about a tumor.

Do symptoms differ in women and men? Or on the left and right side?

Hormonal symptoms depend on which hormone the tumor produces, not on whether it is the left or right adrenal gland. Even a small adenoma can be hormonally active. Size matters for something else: a large mass is more often malignant and can press on nearby organs.

Some signs of cortisol excess are more noticeable in women: menstrual irregularities and excess hair growth on the face and body. Both women and men can develop acne and decreased libido^[3]. These signs are common without any adrenal disease, so on their own they prove nothing. But if there are several of them and they are getting worse, that is a reason to get checked, even if no mass has been found yet^[3].

Signs of male hormone excess are a particular warning sign, especially together with signs of cortisol excess: a woman’s voice deepens, hair grows in a male pattern, and periods stop. Such signs occur with adrenocortical carcinoma, a rare tumor of the adrenal cortex^[7]. About 60% of patients with this cancer first see a doctor because of symptoms of hormone excess, and the next most common complaints are abdominal pain or a feeling of fullness^[7].

Is an adrenal adenoma cancer? Is it dangerous?

An adenoma is a benign tumor. The main questions about it are whether it really is an adenoma and whether it produces hormones.

The first question is most often answered by a CT scan without contrast. If the mass is homogeneous and its density is no more than 10 Hounsfield units, it is benign regardless of size, and no further imaging is needed^[1]. Masses without these features are discussed at a multidisciplinary tumor board and, if needed, investigated further, for example with contrast-enhanced CT or MRI. Surgery is usually offered when the mass is 4 cm or larger and is also inhomogeneous or has a density above 20 units: the risk of malignancy is then high enough^[1].

The danger of a hormonally active adenoma lies in its hormones: a long-standing excess of aldosterone or cortisol harms the heart, blood vessels and metabolism^[2][3]. A nonfunctioning adenoma with a typical CT appearance is usually not operated on^[1]. When surgery is needed, the adrenal gland is most often removed laparoscopically, through a few small incisions^[6]. I perform these operations together with a team of surgical oncologists. How it is done is described on the adrenal tumor surgery page.

What to do if an adrenal mass is found

1. Clarify the density of the mass on CTIf the mass was found on ultrasound, a non-contrast CT is usually done. If you have already had a CT, ask for the density in Hounsfield units on the non-contrast images to be stated and get the images on a disc.
2. See an endocrinologistThey will order hormone tests. A 1 mg dexamethasone suppression test is done for almost everyone, metanephrines when the mass lacks the typical features of an adenoma, and aldosterone and renin if you have high blood pressure or low potassium.
3. Tell your doctor about “ordinary” symptomsBlood pressure that does not come down with medication, recently diagnosed diabetes, rapid weight gain, and attacks of palpitations and sweating all point to which hormone excess to look for.
4. Show the results to a surgeonIf the tests show a hormone excess or the CT appearance is uncertain, send your images and results: the online consultation is free. The treatment plan is discussed with you after a full workup and a tumor board review.

Sources

1. Fassnacht M, Tsagarakis S, Terzolo M, et al. European Society of Endocrinology clinical practice guidelines on the management of adrenal incidentalomas, in collaboration with the European Network for the Study of Adrenal Tumors. Eur J Endocrinol. 2023;189(1):G1–G42. PMID 37318239
2. Adler GK, Stowasser M, Correa RR, et al. Primary Aldosteronism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2025;110(9):2453–2495. PMID 40658480
3. Nieman LK, Biller BM, Findling JW, et al. The diagnosis of Cushing’s syndrome: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2008;93(5):1526–1540. PMID 18334580
4. Lenders JWM, Kerstens MN, Amar L, et al. Genetics, diagnosis, management and future directions of research of phaeochromocytoma and paraganglioma: a position statement and consensus of the Working Group on Endocrine Hypertension of the European Society of Hypertension. J Hypertens. 2020;38(8):1443–1456. PMID 32412940
5. Lenders JW, Duh QY, Eisenhofer G, et al. Pheochromocytoma and paraganglioma: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2014;99(6):1915–1942. PMID 24893135
6. Yip L, Duh QY, Wachtel H, et al. American Association of Endocrine Surgeons Guidelines for Adrenalectomy: Executive Summary. JAMA Surg. 2022;157(10):870–877. PMID 35976622
7. PDQ Adult Treatment Editorial Board. Adrenocortical Carcinoma Treatment (PDQ®): Health Professional Version. PMID 26389393

This article is for general information and does not replace a consultation: the treatment plan is based on your own scans and test results.