Josh Hamilton says he's "off upstairs" because of sinus congestion.

Hamilton is sick with sinus congestion that makes him prone to dizziness and sensitive to the lights at stadiums.

"I'm just off," he said. "However you want to write it, however you want to describe it -- I'm just off."

The condition has been an issue during his career. Hamilton said the latest bout began May 5, but insisted his body still feels "great."