There are no unique physical findings or specific laboratory tests to definitively diagnose Premenstrual Syndrome (PMS). A doctor may attribute specific symptoms to PMS if they are part of a predictable premenstrual pattern. To establish this pattern, your doctor might ask you to keep a detailed record of your signs and symptoms on a calendar or in a diary for at least two menstrual cycles. It is beneficial to note the exact day PMS symptoms begin and when they disappear, as well as the start and end dates of your menstrual periods.
It's important to understand that certain conditions, such as chronic fatigue syndrome, thyroid disorders, and mood disorders like depression and anxiety, can mimic PMS. To help distinguish between these conditions and ensure an accurate diagnosis, your doctor may recommend additional tests, such as thyroid function tests or mood screening assessments.