low testosterone - standard tests before starting therapy?

I recently saw a new endo for symptoms (fatigue, etc.) that I've been dealing w/ for the last 6 months.  She did an ACTH stim test (normal), retested my thyroid (want to up my dose - I'm hypo) and also tested my testosterone.  It was tested a few months ago and was lowish-normal (430).  I'm 37 yrs old, normally developed, no sexual problems.  Just worn out all of the time.

This time the T came back much lower - 250.  And she wants to put me on therapy - probably androgel.

What I want to know is: is it standard practice to test pituitary hormones (LH & FSH) and other hormones (Prog., Aldo., etc.) before starting therapy?  I asked her those questions and she said that I have "classic low-T fatigue symptoms", which is why she wanted to test it, and "no sign of pituitary problems".  I don't know how she can tell just by looking at me.  

Should I be pushing harder to get those tests before I start adding T to my body?  I asked but she doesn't want to do them.  Should I be looking for a new endo?

Also: what would cause T to plummet 200 points in a matter of a few months?  Most of what I've read suggests slow changes are the norm.  Endo thinks I have auto-immune problems, suspects this is  part of that.  But does that mean my immune system is attacking my testicles directly, in addition to my thyroid?  They're at opposite ends of my body!

Thanks for helping me put this all into perspective.

[john911]

Demand that all the test be run and if she says no get a second opinion. The things you listed are good to test also free testosterone, estradiol, shbg, and prolactin. Free testosterone is more important than Therapy will have an effect on your symptoms, however it is permanent and expensive. From what I have heard free testosterone is more important as it is the one available for use by your body. I would think before going onto therapy you should retest at least three times at that low level. What time of the day did you take your test? Are you overweight? Do you live a healthy lifestyle? Going on to therapy could be only a band aid. You need to rule out other causes of your low testosterone before going on therapy. I heard for the gel it is about 350 a month. If you decide not to listen to me I heard that the injections are cheaper and more effective. Going onto therapy eliminates your bodies natural production of testosterone and it might not fully return if you decide to come off of it. There are lots of side effects infertility, growth of prostate cancer (if it is already there). You also need to take estrogen blockers make sure you talk to your endo about estrogen blockers and you need to get blood tests often.

Good Luck

[lowT]

If your endo sais you have "classic symptoms" she's probably right after all it's her speciality.
I would be wanting tests done to identify an auto-immune disease not just a guess.
The tests john suggested would be a good idea, i would also add cortisol to the list.
Depression can cause testosterone to drop and so can weight gain.
In Australia Testogel costs about $90 a month but when prescribed on the pharmacy benefits scheme only costs the consumer about $32.