Which condition is characterized by the absence of menstruation for three cycles or more?

The condition characterized by the absence of menstruation for three cycles or more is known as amenorrhea. This term specifically refers to the cessation of menstrual periods and can occur for various reasons, including hormonal imbalances, excessive exercise, stress, significant weight loss, or underlying health conditions. Primary amenorrhea refers to a situation where menstruation has not occurred by the age of 15 or within 3 years of breast development, while secondary amenorrhea is when menstruation has stopped after having previously been established.

In contrast, dysmenorrhea pertains to painful menstruation, often associated with cramps and discomfort during periods. Menorrhagia refers to abnormally heavy or prolonged menstrual bleeding, which is the opposite of amenorrhea. Oligomenorrhea describes infrequent menstrual periods, typically with cycles longer than 35 days but still occurring, rather than being absent entirely.

Therefore, the distinctive aspect of amenorrhea is its definition related specifically to the absence of menstrual cycles over a set period, which makes this the correct response.