Dan Pfeiffer, a top strategist for President Obama, visited a hospital twice last week with what officials describe as stroke-like symptoms, the White House confirmed to Post Politics.
Pfeiffer, 37, has since returned to work and is being monitored.
"We are happy and relieved to have Dan back at work full time," White House spokeswoman Amy Brundage said. "He's feeling better, listening to his doctors, and focused on helping implement the president’s very full domestic and foreign policy agenda."
Pfeiffer began feeling ill Sept. 4 and stayed at a hospital overnight. After returning to work, he became ill again and returned for two days, Brundage said. He left the hospital on Saturday and began work soon after.
Doctors say Pfeiffer is suffering from what appears to be hypertension.
The news was first reported by the New York Times.