The oldest crystals formed on Earth contain signs that continents existed during the Hadean Eon and were being subducted into the mantle more than 4 billion years ago. If true, this would not only ...

Parts of ancient Earth may have formed continents and recycled crust through subduction far earlier than previously thought.

Audio Timeline Slider: Use the left or right arrow keys to decrease or increase the slider value. Period pain, Payne says, is a key variable in health studies that may seem unrelated to menstruation, ...

Carley Millhone is a writer and editor based in the Midwest who covers health, women's wellness, and travel. Her work has appeared in publications like SELF, Greatist, and PureWow. Qin Rao, MD, is a ...

Dr. Anju Goel, MD, MPH, is a public health consultant and physician with more than 10 years of experience in the California public health system. Heavy periods that cause blood loss can lead to iron ...