Why would someone bleed yellow? That’s what fans were asking themselves after Cleveland Cavaliers forward Cedi Osman’s nose started to leak yellow fluid following a tumble on Sunday, leading to some bizarre online discussions about the meaning of so-called “yellow blood” and what color spinal fluid is.
He had “plenty of people freaked out,” USA Today’s For The Win reported the following afternoon.
The same outlet asked whether or not he had suffered a serious injury and “started leaking spinal fluid” – it also said “he did not.”
Ultimately, Osman returned to the court. But that doesn’t answer the questions burning holes in fans’ pockets.
‘Yellow blood’ meaning explored following Cedi Osman on-court tumble
If Cedi Osman’s skin, the white of his eyes or his mucus membranes had been yellow, then it could have been as a result of jaundice.
People with jaundice tend to have a high level of bilirubin, a yellow-orange bile pigment formed from the breakdown of red blood cells, meaning parts of their anatomy turn a yellowish color.
But Osman doesn’t have jaundice. At least, there isn’t any indication from elsewhere that he suffers from the condition.
In fact, postulations about what leaking yellow blood could mean in the context of Cedi Osman’s fall may not be particularly informative. Sports medicine doctor Brian Sutterer, who has 643K subscribers on YouTube and regularly diagnoses sporting injuries for his channel, reckons the Cleveland forward’s nose was simply leaking mucus.
What color is spinal fluid?
Again, Cedi Osman does not appear to have been leaking spinal fluid – or yellow blood – onto the court on Sunday.
Hamidou Diallo’s arm hits him “right square in the nose, maybe on the left side a little bit,” notes Dr Sutterer. “But this wasn’t anything significant enough that would […] make me think about something like a skull fracture, or a fracture in the bones deep inside the face that would lead to something like a cerebral spinal fluid leak.”
But as a point of interest, it’s still worth knowing about what color spinal fluid is. Cerebrospinal fluid (CSF) is “clear, colorless and watery,” according to Medline Plus. See below.
It flows around your brain and spinal cord. It cushions your brain from sudden impacts and removes waste products from it.
Can an impact to the face like the one that caused Cedi Osman to bleed ‘yellow blood’ cause a spinal fluid leakage?
Apparently, yes. Mayo Clinic’s entry on cerebrospinal fluid notes that a leakage can occur “anywhere in the spinal column.”
A cranial CSF leak, meanwhile, occurs in the skull. While a spinal CSF leak can cause a headache, a cranial one can cause “clear fluid” to leak from the nose or ear.
So it wasn’t too outlandish to consider the notion that Osman may have suffered the kind of impact that would cause him to “bleed” spinal fluid from his nose.
“Sometimes,” continues Mayo Clinic, “CSF leaks develop after very minor events.” And sometimes, it doesn’t even have a known cause. This is called a “spontaneous CSF leak.”
Twitter users discuss the meaning of Osman’s apparently ‘yellow blood’
“What the heck is coming out of his body?” tweeted one observer on Monday morning.
Another responded by saying that while it’s “hard to tell from the video” – it could be “mucus” or “cerebral spinal fluid” – it’s “definitely not blood.”
“I told you but you didn’t believe me,” a TikTok user said over a clip of the match. The incident has led to a surprising number of people joking about how professional basketball players could actually be aliens. “These guys are not human. Yellow blood?”
It wasn’t yellow blood, because blood isn’t yellow. If you’re a platelet donor, you’ll know that platelets alone can appear yellow. But red blood cells mean that whole blood is… red.
Others suggested it could be bile (a la jaundice), cerebrospinal fluid or even Gatorade. Thankfully, it was likely none of those.
For The Win also cites the “medical professional” opinion of Dr Brian Sutterer MD. It adds that if it is indeed mucus, it’s “weirdly runny mucus, but still mucus.”