Cryptomenorrhea is a condition where menstruation occurs but is not visible due to an obstruction of the outflow tract. See also "Mensuration" a term sometimes used to describe Measurement, particularly in the context of Forestry. Specifically the endometrium is shed, but a congenital obstruction in the vagina or on part of the hymen retains the menstrual flow. The endometrium is the inner membrane of the Mammalian Uterus. The vagina (from Latin, literally " Sheath " or " Scabbard " is a fibromuscular tubular tract leading from the Uterus The hymen (also called maidenhead) is a fold of Mucous membrane which surrounds or partially covers the external Vaginal opening A patient with cryptomenorrhea will appear to have amenorrhea but will experience cyclic menstrual pain. Amenorrhoea ( BE) amenorrhea ( AmE) or amenorrhœa, is the absence of a Menstrual period in a woman of reproductive age The condition is surgically correctable. Surgery (from the χειρουργική cheirourgikē, via chirurgiae meaning "hand work" is a medical specialty that uses operative manual and instrumental