Pheochromocytoma Explained

A pheochromocytoma is a rare, usually benign tumour of the adrenal glands that releases extra adrenaline-type hormones. Because these hormones drive the body's "fight or flight" responses, the tumour can cause episodes of high blood pressure, a racing heart, sweating, and headaches. It is diagnosed with specific blood and urine tests followed by imaging.

What a pheochromocytoma is

The adrenal glands sit on top of the kidneys. Their inner part, called the medulla, makes catecholamines — hormones such as adrenaline (epinephrine) and noradrenaline (norepinephrine) that prepare the body for stress by raising heart rate and blood pressure, sharpening alertness, and redirecting blood flow. A pheochromocytoma is a tumour of these hormone-making cells that produces catecholamines in excess and outside the body's normal control.

In a healthy body, catecholamine release is brief and tied to genuine demands such as exercise or fright, then settles quickly. A pheochromocytoma can release these hormones in waves regardless of need, so the body experiences the effects of stress hormones without a matching trigger. This is why symptoms can seem to come from nowhere.

Most of these tumours grow within an adrenal gland. A closely related tumour, called a paraganglioma, can develop in similar nerve tissue outside the adrenal glands — along the spine, in the abdomen, or in the neck — and behaves in much the same way. Because the surplus hormones act powerfully on the heart and blood vessels, the condition is taken seriously even though it is uncommon, and it is generally treatable once identified.

Common signs and symptoms

The hallmark of a pheochromocytoma is episodes, sometimes called spells, in which several symptoms occur together and then ease. Symptoms can also be persistent. They often reflect surges of adrenaline-type hormones and may include:

• High blood pressure, which may come in episodes or be constant
• A pounding, fast, or irregular heartbeat
• Heavy sweating
• Severe headaches
• Tremor, paleness, or a sense of anxiety or dread
• Nausea or unexplained weight change
• Episodes that may be set off by exertion, certain foods, or pressure on the abdomen

The classic combination of episodic headache, sweating, and a fast heartbeat alongside raised blood pressure is a pattern clinicians recognise, although not everyone has all of these features. Some tumours are found incidentally on a scan done for another reason, before any clear symptoms appear.

What causes it

In many people no specific reason for a pheochromocytoma is found. However, a notable share of these tumours are linked to inherited gene changes, which is why family history is often relevant and why genetic counselling is sometimes offered. Several inherited syndromes are known to raise the likelihood of pheochromocytoma or paraganglioma, and some are associated with tumours in other parts of the body as well. Because of this, a clinician may ask about relatives who have had similar tumours or related conditions, and testing of family members is occasionally suggested. When a hereditary cause is identified, it can change how often follow-up is recommended and prompt a wider look for tumours in other locations. Pheochromocytomas can occur at any age and in either sex, and they are uncommon, so a single episode of a fast heartbeat or sweating is far more likely to have an everyday explanation than to point to one of these tumours.

How it is diagnosed

Diagnosis usually starts with measuring the breakdown products of adrenaline-type hormones, which tend to be more stable and informative than the hormones themselves. Testing is planned carefully because medicines, stress, caffeine, and certain foods can affect results, and a clinician may give specific preparation instructions. Common steps include:

• Metanephrines in blood or urine — these breakdown products of catecholamines are the main screening tests; a 24-hour urine collection is sometimes used.
• Catecholamines — adrenaline-type hormones themselves may also be measured in some situations.
• Imaging — a scan such as CT or MRI of the adrenal glands and abdomen can locate a tumour once biochemical tests are abnormal.
• Specialised scans — in some cases additional functional imaging is used to find tumours outside the adrenal glands or to check for spread.
• Genetic testing — may be offered because inherited causes are common, and it can guide follow-up for the individual and relatives.

The table below outlines the main biochemical clues. It is illustrative only; reference ranges vary by laboratory and method, and results must be interpreted by a clinician alongside symptoms and imaging.

For background on hormone testing in general, see our blood tests and hormones sections, and our conditions overview for related adrenal topics such as primary aldosteronism.

How it is generally managed

Management is decided with a specialist team and usually centres on removing the tumour with surgery once the diagnosis is confirmed. Before surgery, clinicians typically use medicines for a period to control blood pressure and reduce the effects of the surplus hormones; this preparation is an important safety step that helps make the operation safer. After treatment, ongoing monitoring is common, particularly when an inherited cause is found, because new tumours can develop over time. General treatment principles are outlined in our treatments section. This page is educational and does not describe doses; it is not a substitute for personalised medical advice.

Possible complications and when to seek care

The chief concern with a pheochromocytoma is the effect of sudden, large surges of stress hormones on the heart and blood vessels, which can cause sharp spikes in blood pressure. For this reason, the condition is approached cautiously and treated by experienced teams. Anyone with episodes of severe headache, chest pain, a markedly irregular or very fast heartbeat, or sudden severe blood-pressure symptoms should seek prompt medical attention. A person already diagnosed should follow their clinician's advice on which situations or medicines to be careful about.

Living with a pheochromocytoma

After successful treatment, many people do well, but follow-up matters because tumours can occasionally return or appear elsewhere, especially with an inherited cause. Long-term monitoring usually includes periodic biochemical tests and clinical review. Understanding personal and family risk, attending follow-up appointments, and reporting new symptoms early all help keep care on track. Where genetic testing identifies a hereditary cause, relatives may be offered screening so that any tumour can be found early.