Which is raised in polycystic ovarian syndrome?

**Core Concept**
Polycystic ovarian syndrome (PCOS) is a complex endocrine disorder characterized by ovulatory dysfunction, hyperandrogenism, and polycystic ovarian morphology. The underlying pathophysiology involves insulin resistance, hyperinsulinemia, and an imbalance of sex hormones.

**Why the Correct Answer is Right**
The correct answer is raised LH/FSH ratio. In PCOS, there is an increase in the production of androgens due to ovarian stroma hyperplasia and insulin resistance. This leads to a negative feedback on the hypothalamus, resulting in decreased GnRH secretion and, subsequently, a decrease in FSH production. However, the increase in LH production, primarily due to its shorter half-life and increased sensitivity to GnRH, results in an elevated LH/FSH ratio.

**Why Each Wrong Option is Incorrect**
**Option A:** Androgen levels are indeed elevated in PCOS, but this is not the primary issue. The LH/FSH ratio is more specific to the pathophysiology of PCOS.

**Option B:** Insulin resistance is a key component of PCOS, but it is not the answer being sought. The question is asking for a hormonal imbalance specific to PCOS.

**Option C:** Ovarian cysts are a characteristic of PCOS, but they are not the correct answer. The LH/FSH ratio is a more direct indicator of the hormonal imbalance.

**Option D:** Hyperprolactinemia is not a primary feature of PCOS. The LH/FSH ratio is a more specific indicator of the hormonal imbalance in PCOS.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the LH/FSH ratio is a sensitive marker for PCOS, particularly in women with regular menstrual cycles. A ratio of 2:1 or higher is often indicative of PCOS.

**Correct Answer: C. LH/FSH ratio**