What kinds of tests are there that can diagnose secondary amenorrhea?

Pituitary disease. Primary implies an ovarian disorder. Secondary implies a pituitary disorder. Elevated prolactin, low lh, fsh, high tsh, starvation (anorexia), bulemia and excessive exercise all effect the pituitary axis. Need to have the above hormones checked if there is no other reason (anorexia, excessive exercise...).