Amenorrhoea is the absence of menses. Primary amenorrhea is defined as the failure of menses to begin once a woman reaches 16 years of age, whether or not other pubertal changes such as breast development/pubic or axillary hair are present. Secondary amenorrhoea is the absence of menses for the length of time equal to three consecutive normal menstrual cycles, in a woman who has previously experienced cyclical menses. Interference with hypothalamic/pituitary functioning plays a major role in the disorder. Amenorrhoea may be present with other conditions or abnormalities, including hirsutism, obesity, and galactorrhea.

Aetiology

• Pregnancy—high hCG
• Anatomical defects of the uterus or outflow tract—normal FSH: imperforate hymen, transverse vaginal septum, or vaginal or uterine aplasia (Primary); uterine adhesions (Asherman‘s syndrome: Secondary)
• Ovarian—high FSH: Dysfunction/dysgenesis of ovaries (Primary); premature ovarian failure, e.g. due to chemotherapy or radiation (before the age of 40: Secondary); spontaneous menopause, beginning as early as age 40 (Secondary)
• Hyperprolactinaemia—varied causes
• Hypothalamic/pituitary dysfunction—low to normal follicle-stimulating hormone (FSH), impaired GnRH production: e.g. intracranial tumours, post-partum necrosis (Secondary); Primary GnRH deficiency.
• Functional hypothalamic/pituitary impairment—e.g., malnutrition/extreme weight loss (anorexia), strenuous exercise of long duration, stress, psychological disorders, drug abuse, autoimmune endocrine disease, immune deficiency, occult malignancy, diabetes mellitus, extreme obesity
• Hyperandrogenism—low-normal FSH: secretion of excessive testosterone (e.g., polycystic ovarian syndrome: Primary/Secondary), anabolic steroid use
• Pseudohermaphroditism—high luteinizing hormone (LH): Defective testosterone synthesis with excessive testosterone levels (Primary)
• Breast-feeding
• Following cessation of oral contraceptive use

Symptoms and Signs

• Primary: Headaches, blood pressure or visual field abnormalities, acne, short stature (Turner's syndrome), tall stature (eunuchoidism/gigantism)
• Secondary: Nausea, breast enlargement, hot flushes, headaches, visual field abnormalities, thirst, polyuria, goitre, skin darkening, anorexia, alcoholism, Cushing's syndrome, cirrhosis, renal failure