Catatan

Patients seldom present to their doctors with diagnoses—rather, they have
symptoms or signs. The major challenge of medicine is being able to talk to

the patient and obtain a history, then carry out a physical examination look-
ing for pointers to their likely underlying problem. Our elders and, some

would argue, betters in medicine had fewer tests available to them than we
have today, and their diagnoses were often made solely from the history
and examination. Of course, they would claim that their clinical acumen
and skills were greater than ours, and that we rely too heavily on the huge
armoury of laboratory and other investigations available today. This, in part,
is probably true, but we cannot ignore the fact that advances in science and

technology have spawned a bewildering array of very useful and sophisti-
cated tests that help us to confirm our diagnostic suspicions.

By ‘test’ we mean the measurement of a component of blood, marrow,
or other body fluid or physiological parameter to determine whether the
patient’s value falls within or outside the normal range, either suggesting the
diagnosis or, in some cases, actually making the diagnosis for us.