Costa Rican President Oscar Arias has a benign cyst on his vocal chords and must not speak for the next four weeks, said doctors at a private clinic in the U.S. city of Philadelphia, where the president underwent medical exams yesterday.

If he does not feel better after a month, Arias will explore whether to undergo surgery, according to a Casa Presidencial press release.

The president will return to Costa Rica Saturday after spending four days abroad with his daughter, Silvia Eugenia Arias.