What term describes menstrual cycles that span 45 to 90 days?

The term that describes menstrual cycles lasting 45 to 90 days is oligomenorrhea. This condition is characterized by infrequent menstrual periods, specifically defined as having cycles that occur less frequently than every 35 days but more frequently than 90 days. This means that if a woman's cycles are prolonged and she only experiences menstruation a few times a year, it may fall under the category of oligomenorrhea.

In a broader context, oligomenorrhea can be associated with various factors, including hormonal imbalances, stress, or changes in body weight, which can affect the hypothalamic-pituitary-ovarian axis. Understanding this term is crucial for recognizing and addressing underlying health issues related to reproductive health.

The other terms, such as secondary amenorrhea, which refers to the absence of menstruation for three or more consecutive cycles in someone who previously had regular cycles, and primary amenorrhea, which is the absence of menstruation by age 15 in someone with the normal development of secondary sexual characteristics, do not describe infrequent cycles but rather a total cessation of menstruation. Menorrhagia refers to abnormally heavy or prolonged menstrual bleeding, which is also distinct from the condition described in the question.