MMA is a violent profession that involves the daily practice of getting hit in the face. It’s not for the faint-hearted, not even in the UFC, the best MMA promotion in the world. If you suffer a brutal knockout, it almost guarantees some form of brain damage. But, how much brain damage do UFC fighters have?
Research shows that brain injuries among MMA fighters (including UFC) range from 25-33% of individuals. The percentage gets higher as you move up weight classes. It also gets higher parallel to the fighter’s active fighting years.
That means the longer you’re in the game, the more likely you’ll suffer from brain injury or trauma. There are many variables to consider, though. Not every concussion has to lead to brain damage but is always classified as a brain injury. Therefore, you need to go deeper into the numbers if you want the full picture.
Do UFC Fighters Have Brain Damage?
As I mentioned in the intro, research in 2018 suggests that around 24% of MMA fighters suffer some form of brain damage. That means almost every fourth fighter has some kind of brain damage. 
The same research found that over 71% of all MMA-related injuries are head injuries, including hematomas, concussions, fractures, etc.
Brain damage can come from a single punch knockout that causes a significant concussion, resulting in permanent damage to the brain.
However, the more frequent issue that happens to the fighters is CTE or chronic traumatic encephalopathy.
For those unfamiliar with the term, CTE is also known as boxer’s dementia – brain damage that happens not due to a single blow to the head but repetitive strikes and head trauma throughout the fighter’s career.
That means the longer the fighter’s career is, the higher the chance of developing CTE or similar brain damage after their career is over.
To put things into perspective, another research of UFC bouts concluded that almost a third of UFC fights end with a traumatic brain injury (most commonly, a (T)KO). Among the fights resulting in a technical knockout, around 90% came after a series of repetitive strikes to the head, usually unguarded. 
Finally, there was an average of 2.6 strikes to the head after the opponent was already knocked out unconscious, or at least knocked down to the point where they cannot defend themselves.
So yes, many UFC fighters suffer from brain damage. Of course, most of them don’t have chronic symptoms or conditions that harm their life quality dramatically, and many never suffer long-term consequences in terms of brain damage.
But, there are some cases where brain damage stemming from years of MMA fighting becomes extremely severe, even life-threatening.
What Percent of UFC Fighters Get Brain Damage?
According to the research I’ve mentioned earlier, around a third of all UFC fights end with fighters dealing with some kind of brain trauma (most often, concussions). Sometimes, it comes from repetitive head strikes, but we can be sure that brain trauma happens in fights that end in KO/TKO.
A 2019 research revealed that weight divisions played a crucial role in KO/TKO finishes. For instance, the female strawweight division saw 7.9% bouts resulting in KO/TKO, but 52.1% of male heavyweight bouts finished with such an outcome. 
It is hard to precisely determine how many UFC fighters end up suffering from long-term brain damage because symptoms can appear long after their active MMA career is finished. Situations like that are not that rare, though, especially for long-tenured fighters with 15 or more years of fighting experience.
According to a study where the researcher Sarah Banks studied MRI scans for 135 MMA fighters and boxers, those with only five years of fighting experience had no major discrepancies from non-fighters brains. 
However, fighters with 15 years of fighting or more experience showed up to 10% lower brain volume in certain areas, especially those that regulate memory, learning, emotions, and movement.
It is safe to say that long-term brain damage happens often enough to have the fighters aware of the risks. New rule implementations made huge steps in making MMA safer, but getting hit over the head is hard to keep safe from when you step in that cage.
How Many Brain Injuries Have There Been In The UFC?
As I said, it’s very hard to determine how many fighters suffer brain damage in the cage or end up having long-term problems. Apart from KO/TKO statistics and research, we have seen dozens of stories about fighters that suffered serious brain damage in the UFC.
Most lately, we’ve heard about the UFC veteran Spencer Fisher having CTE that permanently rendered him unable to work. After Fisher’s statements, UFC president Dana White said, “it was just part of the gig.” It sounds harsh, but it’s the truth. Fisher is just one of many suffering from the same post-career issues.
Krzysztof Soszynski suffered a brutal knockout against Igor Pokrajac at UFC 140, after which he was forced to retire due to brain damage and memory loss. He said he started forgetting his words and even had trouble counting backward from 20 to 10, among other difficulties.
CTE is not rare among fighters in the heavyweight and light heavyweight divisions, as the punches are much more powerful. Renato Sobral had a 16-year MMA career and got knocked out seven times in that span. His CTE symptoms include seizures, memory problems, balance issues, and the damage even caused blindness in his left eye.
Former UFC heavyweight Tim Hague suffered the worst possible fate imaginable. He got badly knocked out in a boxing match in 2017, leading to fatal hemorrhages on his brain, from which he passed away two days after the match.
His family sued the responsible commission for gross negligence after the autopsy revealed that Hague already had CTE. He probably had it for years before his death due to several hard knockout losses in his late MMA career.
The Athletic surveyed MMA fighters to see how many are aware or worried about potential long-term brain damage. 
Over 55% of them claimed to expect brain injuries to affect their lives in the future. Stars and former champions like Khabib Nurmagomedov and Anthony Pettis expressed their concerns about brain injuries in post-career life.
Brain damage, short-term or long-term, is a problem in full-contact combat sports, especially in the MMA. Fighters in the UFC are exposed to the same dangers, so the more fighters are aware of the dangers, the more can be done to protect them in the octagon.