What are the hallmark symptoms commonly associated with premenstrual syndrome (PMS)?

The hallmark symptoms commonly associated with premenstrual syndrome (PMS) include mood swings, irritability, and bloating. PMS is a condition that occurs in the luteal phase of the menstrual cycle, typically one to two weeks before menstruation begins. The symptoms are primarily related to hormonal fluctuations, particularly changes in estrogen and progesterone levels, which can significantly affect mood and physical well-being.

Mood swings and irritability are particularly notable as they can be quite disruptive to a woman's emotional state during this time. Bloating is also a very common physical symptom experienced by many women, and it is often attributed to fluid retention and changes in gastrointestinal function as a result of these hormonal variations.

In contrast, the other options include symptoms that are not typically associated with PMS; for example, severe abdominal pain and heavy bleeding are more indicative of conditions like dysmenorrhea or endometriosis rather than PMS. Changes in appetite and insomnia can occur, but fever is not a typical symptom of PMS and suggests an underlying infection or other systemic issue. These distinctions help clarify why mood swings, irritability, and bloating are considered the key characteristics of PMS.