Senator Chuck Grassley (R., Iowa) has received antibiotic infusions at a hospital to treat an infection, his office confirmed Tuesday.

“He is in good spirits and will return to work as soon as possible to treat an infection,” a statement from his office reads. The 90-year-old’s office did not specify the cause of the infection, when his symptoms began, or when he was admitted to the hospital.

The Hawkeye State’s senior senator — the oldest member of the upper chamber of Congress — won his first Senate election in 1980 and has been re-elected seven times since.

Grassley’s health had not been in question before today, and he called in to Fox News on Saturday to discuss Monday’s Iowa caucuses.