WASHINGTON - U.S. Defense Secretary Lloyd Austin has been hospitalized again and was put under general anesthesia on Monday to address a bladder issue. It was his second hospitalization this year following prostate cancer surgery in December.

Here is an explanation of what has been revealed publicly about Austin's medical issues.

WHY IS AUSTIN BACK IN THE HOSPITAL?

Austin, 70, returned to the hospital on Sunday due to symptoms suggesting an emergent bladder issue, Walter Reed National Medical Center said in a statement. He was placed in the critical care unit after a series of tests, it added, and on Monday underwent non-surgical procedures under general anesthesia to address his bladder issue. The nature of this medical issue has not been fully disclosed.

The hospital said in a statement that a successful recovery is anticipated and that Austin will be closely monitored overnight.

Neither the hospital nor the Pentagon have said whether Austin's latest health issue was a further complication from his original prostate cancer diagnosis and surgery or was a new condition.

HOW LONG WILL AUSTIN REMAIN HOSPITALIZED?

While it remained unclear how long Secretary Austin would remain hospitalized, the hospital said a prolonged stay "is not anticipated." The hospital also said it is anticipated that Austin will be able to resume his normal duties on Tuesday.

His official duties were transferred on Sunday to the Pentagon's No. 2 official, Deputy Secretary of Defense Kathleen Hicks. Austin canceled a planned trip to Brussels this week for a meeting of NATO defense ministers. His participation in a virtual Ukraine defense meeting is also tentative, depending on his health status, officials said.

"The current bladder issue is not expected to change his anticipated full recovery. His cancer prognosis remains excellent," the hospital said.

WILL AUSTIN NEED TO RESIGN?

Austin previously said he had no plans to resign. President Joe Biden has expressed confidence in Austin, even after the Pentagon chief kept his first two hospitalizations secret - even from Biden.

WAS THIS A SURPRISE?

Austin appeared at a news briefing on Feb. 1, saying, "I'm recovering well, but as you can see, I'm still recovering."

At the time, Austin said he was still experiencing some leg pain and doing physical therapy.

WHEN WAS AUSTIN'S PROSTATE CANCER DETECTED...