Why are there so many different types of tests for pheochromocytoma, and which ones should I have performed?

Two major types. Plasma-free catecholamines (epinephrine and norepinephrine) and metanephrines (metabolites of catecholamines) can be measured after an 'attack' of pheochromocytoma, using a blood sample. This is a very useful test, simple to collect. Alternatively, 24-hour urine testing for catechol and metaneph can also be helpful after an 'attack'. Other testing using drugs are complicated and rarely needed.
Because . There are lots of ways to skin a cat. The one your doctor orders is the one that's right for you.