Muhammad Ali was brought to the ICU after house guests found the boxer unresponsive. According to reports, he is currently undergoing tests to find out what is wrong. A source told Radar Online, “He wasn’t responding. He went to bed Tuesday night, but didn’t wake up in the afternoon or evening the next day. He was sleeping for 24 hours.” The source added, “They thought he might be too exhausted.” This recent trip to the hospital comes just one week after Ali was treated for a urinary tract infection.

Bob Gunnell, a spokesman for Ali, said that the legendary boxer was brought to the hospital again for further care following the previous hospitalization. “There were still issues with the urinary tract infection,” Gunnell said. According to reports, Ali is expected to be released on Friday, the day before his birthday.

Legendary boxer Muhammad Ali hospitalized again http://t.co/q78gD8iSub pic.twitter.com/dIJIInpvjT

— PIX11 News (@PIX11News) January 16, 2015

Ali was diagnosed with Parkinson’s disease three years after he retired in 1981. Ever since then, he decided to devote his time to humanitarian efforts. However, his public appearances have diminished over recent years due to his deteriorating health. Despite this, Ali still enjoys going out and watching sports events, especially those involving his hometown of Louisville, Kentucky.

While Ali hasn’t been seen publicly for a while, he remained active in social media prior to his hospitalization. Ali is an active Twitter user and has more than 405,000 followers. Back in December, he also signed up for the popular social networking site, Instagram. Ali has so far posted nine photos and has gained more than 120,000 followers.

Ali’s first picture on Instagram shows him smiling, assuring fans that he’s still feeling well. He also posted a message to his beloved Louisville Cardinals, saying, “#Louisville Game Day! Go Cards!”

A photo posted by Muhammad Ali (@muhammadali) on Nov 29, 2014 at 12:13pm PST

Known as “The Greatest”, Ali won the World Heavyweight title three times and had iconic rivalries with boxers Joe Frazier and George Foreman.