Secretary of State Hillary Clinton sustained a concussion last week after becoming extremely dehydrated and fainting while suffering from a stomach virus, the State Department said.

The 65-year-old Clinton is recovering at home and has been advised by her doctors to continue to rest and avoid strenuous activity and cancel all work events for the next week. She had been scheduled to testify before a pair of congressional panels looking into the Sept. 11 attack against a diplomatic outpost in Benghazi, Libya.

Clinton was diagnosed with a concussion Thursday after fainting at home earlier this week, according to a State Department official who spoke on the condition of anonymity because he was not authorized to discuss Clinton’s injury publicly. The doctors did not determine it to be a “severe” concussion, the official said.