The State Department says Secretary of State Hillary Rodham Clinton, who skipped an overseas trip this past week because of a stomach virus, sustained a concussion after fainting.
She's now recovering at home and being monitored by doctors. NBC's Savannah Guthrie reports that Clinton's fall occurred earlier this week, though exactly when Clinton had her scare is not known.
An aide, Philippe Reines, says Clinton will work from home next week, at the recommendation of doctors.
Congressional aides do not expect her to testify as scheduled at congressional hearings on Thursday into the Sept. 11 attack against a U.S. diplomatic outpost in Benghazi, Libya, that killed four Americans, including the U.S. ambassador.
The aides spoke on condition of anonymity because they weren't authorized to publicly discuss Clinton's status.
The department says Clinton was dehydrated because of the virus and that she fainted, causing the concussion. Clinton backed out of a trip to North Africa and the Persian Gulf on Monday because she was sick. She caught the virus during a recent visit to Europe.
The 65-year-old Clinton, who's expected to leave her job soon after serving as America's top diplomat during President Barack Obama's first term, is known for her grueling travel schedule and is the most traveled secretary of state, having visited 112 countries while in the job.