Part of what makes medical emergencies so scary is that, by nature, they can happen completely unexpectedly.

How are people contracting bird flu? Can people pass bird flu to each other? Is there bird flu in Oakland? All your questions ...

Stocks Sink as Investors Worry About China’s A.I. Advances A jolt of panic hit technology stocks on Monday, with investors rattled by fears that A.I. advances by Chinese upstarts could threaten ...