--would have a lot to do with whether a "smoking gun" cause is found for one's symptoms early on, and whether or not one gets a firm diagnosis.

There are some problems which tend to evolve over time, and one may initially have negative or ambiguous test results that change over time, such as with many chronic autoimmune conditions (Cycleops can talk a lot about that). And, of course, there are some situations in which constant testing is warranted--such as blood sugar in diabetics--to ensure there are not acute crises.

The most difficult situations are those in which there aren't unequivocal results or diagnoses. The idiopathic are always wondering if another test down the road will show SOMETHING that might explain their symptoms--sometimes eventually it will, sometimes not . . .

The sad part about this is that economic considerations most often trump clinical considerations in determining how much testing gets done.