Pheochromocytoma is an unusual but potentially devastating tumor. Although a 
high index of suspicion is necessary, the likelihood of a pheochromocytoma is 
lower in the absence of the typical symptoms and findings. Nonetheless, 
screening must be broadened to include patients with a lower risk of the 
disease, such as those with resistant or labile hypertension who are minimally 
symptomatic. Extensive diagnostic evaluations should be reserved for those whose 
clinical or laboratory findings are more suggestive. Symptoms in a group of 
patients in whom a pheochromocytoma was seriously considered but excluded 
overlap symptoms in patients with a pheochromocytoma. Certain symptoms are 
useful: flushing to suggest a non-pheochromocytoma illness; visual symptoms, 
flank pain, and pallor to suggest that a pheochromocytoma is more likely. 
Combinations of symptoms can be of value: 2 or more symptoms from the triad of 
headache, palpitations, and diaphoresis were present in the majority of 
pheochromocytoma patients, but in a smaller number of non-pheochromocytoma 
patients. The presence of the entire triad is more specific, but less sensitive. 
New hypertension, or hypertension associated with unexplained orthostatic 
hypotension, are suggestive of an underlying pheochromocytoma. Twenty-four-hour 
urine studies are consistently abnormal in patients with a pheochromocytoma, but 
are also elevated in a significant proportion of non-pheochromocytoma patients. 
Values greater then 1.5-2-fold above the upper limit of normal are very 
suggestive that a pheochromocytoma is present, and warrant a more intensive 
subsequent evaluation. Imaging studies are reliable in the diagnosis of 
pheochromocytoma, and can help to confirm or exclude the disease. Patients with 
a higher clinical likelihood and any elevated urinary testing, or with a lower 
clinical likelihood and persistently and/or significantly elevated urinary 
testing, should have imaging studies performed. This combination of clinical 
screening, 24-hour urinary testing, and imaging studies is a useful and reliable 
approach to patients suspected of harboring a pheochromocytoma.