@Sqad - Your prejudices are showing :)
Short answer O_G. I would contend that the problem is not that the tests do not explain the symptoms - rather, that the medical professional with whom you are consulting has not communicated the link between a result and your symptoms.
It is that interface and the communication between medical professional and patient that is the problem. Now couple that with a low level of scientific/ biochemical understanding amongst the general population ,and the time constraints upon medical professionals, and it is not too surprising that the link between a diagnostic test and the symptoms experienced by the patient are not necessarily fully explained.
The link between daignostic test and disorder is often simple enough to explain - Anaemia and low Haemoglobin for example. Tired all the time, shortness of breath and all that.
But sometimes the link between the 2 can be far more complex and difficult to explain in a short consultation. The meaning of a High ESR, for example, or a borderline high blood sugar level.
We are all individuals, all with our own perception and response to pain or sense of being unwell. Many symptoms are common to a bewildering array of possible causes, so the diagnostic tests will require careful interpretation.
However, there are many resources available to the patient now, more than ever before, which can go some way toward offering greater understanding of what those tests can mean.
Or you can do what I advise. Take a notebook. Note your symptoms. Note your test results. Ask your medical professional to explain how they relate. If you are put on a drug therapy - find out how long they intend for you to be on the drug, found out the period of time for the review, ask about possible common side effects to look out for.
Its all about communiication folks, and the general public have some obligations in this area too :)