Functional Hypothalamic Amenorrhea (FHA) is not a rare kind of secondary amenorrhea. It is not related to specific systemic or organic causes, so various stressors may occur simultaneously, triggering the disappearance of the menstrual cyclicity. Specific neuroendocrine events are at the basis of FHA, and these might be activated by a variety of signals, both from the central nervous system (CNS) as well as coming from the periphery and related to excess energy consumption. The optimal clinical approach relies on a correct diagnosis through the anamnestic evaluation of the patients and from hormonal determinations. Treatments have to be chosen accordingly, trying to face all the aspects of the FHA that each single patient has.