What Kind of Doctor Do I Need? Slideshow Dental (Oral) Health Quiz Causes of a Heart Attack Slideshow Progesterone: A female hormone, the principal hormone that prepares the uterus to receive and sustain fertilized eggs. From Healthy Resources When Prostate Cancer SpreadsHow Well Are You Living With AS?Protecting Your Immune System Featured Centers When Prostate Cancer SpreadsEssential Tips to Manage DiabetesWhat Is Cystic Fibrosis? What Causes It? Health Solutions From Our Sponsors Kept Your Wisdom Teeth? What is TAVR?