All of the following are features of pheochromocytoma except -
Most adrenal medullary tumours secrete norepinephrine or epinephrine or both and produce sustained hypertension. 
Sometimes catecholamines are released in spurts which produce paroxysmal hypertension.

Hypertension when episodic is accompanied by other manifestations of catecholamine excess such as : 
-Palpitations
-Tachycardia
-Feeling of anxiety
-Excessive sweating
Headache, palpitation and diaphoresis constitute the classic triad of pheochromocytoma.
Paroxysmal hypertension return to normal when catecholamine level becomes normal.
Orthostatic hypotension occurs because of diminished plasma volume and blunted baroreceptor reflex.
Hypertensive paraoxysm
Headache
Orthostatic hypotension
Wheezing