Sources tell Us Weekly that doctors will not know the full extent of the damage to Lamar Odom's brain and body for a while -- get the exclusive scoop here. Credit: Jeff Kravitz/FilmMagic

Time will tell all. Lamar Odom, who remains hospitalized after being found unconscious on Oct. 13, has multiple medical hurdles to overcome in his ongoing journey toward recovery, multiple sources reveal to Us Weekly exclusively — and they're serious issues.

A source close to the situation tells Us that the former NBA player, 35, is "definitely" in need of a kidney transplant. As reported by TMZ this past weekend, Odom has been suffering from major kidney failure and is currently on dialysis.

The source tells Us that Odom has good and bad moments daily, and showed some progress. "He can say a few words," the insider tells Us of Odom, who has yet to speak in full sentences. "He's doing a tiny bit better, but he has a very long road back to full recovery — if that."

Another source tells Us that Odom's brain injury is currently "of the most concern" for his famous in-laws, who, like Khloe, rushed to be by his side at Sunrise Hospital in Las Vegas when he was initially hospitalized.

The damage to Odom's brain would have been caused by the reported dozen strokes he suffered when he was found unconscious and transported to the hospital in critical condition. "That's the most serious thing he's dealing with," the second insider adds to Us. Both sources tell Us that the full extent of damage done to Odom's body, brain included, will remain unknown for a while.

Says the first source: "The doctors just don't know the extent of all the damage yet. There are still a lot of tests that need to be done." The second insider echoes the first and tells Us: "He'll get more of his motor skills back gradually, but cognitively, he's not where he used to be."

Amid Odom's incremental improvement, Khloe resumed updating content on her paid app, which launched shortly before the incident at the Love Ranch South brothel occurred.

"Thank you dolls SO much for your patience while I needed some time off," Kardashian wrote on her website on Monday, Oct. 26. "I'm excited to be back in the mix bringing you some awesome content. Your love and support has meant the world to me. XOXO, Khloe."

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics, and more delivered straight to your inbox!