What are the primary causes of amenorrhea?

Amenorrhea, the absence of menstruation, can be caused by a variety of factors, and understanding these primary causes is essential for diagnosis and treatment. Pregnancy is one of the most common and well-known causes of amenorrhea, as it leads to significant hormonal changes that halt the menstrual cycle. Hormonal imbalances, whether due to thyroid disorders, polycystic ovary syndrome (PCOS), or disruptions in the hypothalamic-pituitary-ovarian axis, can also prevent menstruation from occurring. Additionally, excessive exercise, particularly when combined with low body fat, can disrupt the hormonal signals necessary for menstruation, a condition often observed in athletes or individuals engaging in intense physical activities.

The other options, while they may relate to conditions affecting female reproductive health, do not encompass the primary reasons for amenorrhea as comprehensively. For instance, while excessive weight gain and hormonal therapy can influence menstrual cycles, they do not represent the most common causes. Genetics and aging are factors that can influence fertility and menstrual regularity over the long term but are not immediate causes of amenorrhea. Lastly, sexually transmitted infections (STIs) and pelvic surgery can lead to complications that might affect menstrual cycles, but these are not the primary