smallermediumlarger Definition of PMDD Take the PMDD Quiz! A Visual Guide to PMS Slideshow PMDD: Premenstrual dysphoric disorder.Last Editorial Review: 3/19/2012 Search MedTerms:Back to MedTerms online medical dictionary A-Z List Need help identifying pills and medications? Use the pill finder tool on RxList. Share this Article: Facebook Twitter Email Print Women's Health Newsletter Sign up to stay informed with the latest women's health-related updates on MedicineNet delivered to your inbox FREE! BONUS! Get a Free PDF Women's Health Report when you sign up! Sign up for more topics!