Lamar Odom is fighting for his life after falling into unconsciousness at Dennis Hof's Love Ranch South in Pahrump, Nevada ... TMZ Sports has learned.
Sources at the Love Ranch tell us ... 35-year-old Odom arrived at the Ranch on Saturday and was partying with the girls for days. A source at the Ranch said Lamar was taking an herbal substitute for Viagra.
We spoke with Hof ... who tells us on Tuesday afternoon, a woman went into Odom's room in the VIP suites and found him unconscious. The woman rolled the former NBA star over and saw fluid streaming out of his mouth.
An ambulance took Lamar to Pahrump hospital, where doctors intubated him ... an indication he could not breathe on his own.
We're told Lamar is being airlifted from the hospital to Las Vegas for more treatment.
Our sources tell us, "It doesn't look good."
Story developing ...