Which condition is characterized by irregular menstrual cycles and increased hair growth?

Polycystic ovarian syndrome (PCOS) is a condition associated with hormonal imbalances that can lead to irregular menstrual cycles and increased hair growth, known as hirsutism. In PCOS, the ovaries may develop multiple cysts, and the hormonal imbalance often involves elevated levels of androgens, which are male hormones that can contribute to excessive hair growth in women. Alongside these symptoms, individuals may also experience weight gain, acne, and difficulty conceiving.

The other conditions listed do not typically encompass both irregular menstrual cycles and increased hair growth to the same extent. Hypothyroidism can affect menstrual regularity but is not directly linked to increased hair growth. Premenstrual syndrome primarily involves emotional and physical symptoms related to the menstrual cycle rather than the hormonal imbalances seen in PCOS. Menopause marks the end of menstrual cycles and leads to a reduction in estrogen levels, which generally does not cause hirsutism but may lead to hair thinning. Thus, PCOS is uniquely characterized by the combination of these two symptoms.