Amenia, more commonly referred to as amenorrhea, is characterized by the absence or halt of menstruation. Amenorrhea is typically categorized into primary and secondary types. Primary amenorrhea occurs when menstruation does not begin during puberty. In contrast, secondary amenorrhea happens when menstruation begins normally but then ceases. The lack of menstruation during pregnancy is a natural form of amenorrhea, considered physiological as it is entirely normal and not due to any disorder. Another example of physiological amenorrhea is the absence of menstruation during breastfeeding. The term "amenorrhea" is derived from three Greek roots: "a-" meaning no, "men" meaning month, and "rhoia" meaning flow, collectively signifying "no monthly flow."
