After suffering various symptoms i had some blood tests which included tsh, 9am cortisol, dhea, kidney function, liver function and full blood count. all normal apart from very low dhea what can i do?

Negative workup: When the labs are nonrevealing, the task of ruling out serious illness falls to the clinician and patient. Porphyria, arsenic poisoning, fibromyalgia, Lyme, early lupus, polymyalgia rheumatica, some of the hydrocephalus variants, parasomnias, early sprue, and a few dozen others won't show up on a "fishing expedition" at the lab -- though I'm glad the tests were done.