Which symptom documented in a menstrual diary is diagnostic of PMS?

Irritability is recognized as a key symptom in the diagnosis of premenstrual syndrome (PMS). PMS is characterized by a range of emotional and physical symptoms that typically occur in the luteal phase of the menstrual cycle and resolve with the onset of menstruation. Among these symptoms, emotional changes like irritability, mood swings, and anxiety are particularly common and can significantly affect daily functioning.

In the context of PMS, irritability often manifests as a heightened emotional response to stressors or interpersonal interactions. This symptom is particularly useful for diagnostic purposes because it is not only common but also tends to have a cyclical pattern that correlates with the menstrual cycle, making it more distinctive for PMS compared to other symptoms.

While decreased libido, menstrual cramps, and dyspareunia can certainly accompany the menstrual cycle, they are not specific enough to PMS alone. Decreased libido can occur due to various factors unrelated to PMS, menstrual cramps are often associated with dysmenorrhea rather than PMS, and dyspareunia (painful intercourse) can arise from a range of medical issues, not just those connected to premenstrual changes. Therefore, irritability stands out as the diagnostic symptom that is strongly associated with PMS, illustrating the emotional component of