"I was in a lecture about concussions and of the 10 symptoms the guy mentioned, I had eight," Silva, 42, said. "The symptoms would be, for example, mood swings, getting angry very fast, forgetting some things, having difficulty sleeping."
Silva most recently competed in Bellator in September, losing by second-round TKO to Quinton "Rampage" Jackson.
Silva, a native of Curitiba, Brazil, rose to prominence in Pride Fighting Championships in the late 1990s and early 2000s. He won the promotion's middleweight title in 2001 and held that honor until 2005. Silva was the first fighter in history to win both a Pride championship and the Pride Grand Prix.
"The Axe Murderer" joined the UFC in 2007 and went 4-5 in nine fights before signing with Bellator.
Silva (35-14), who had seven losses by either knockout or TKO, said he plans on donating his brain for chronic traumatic encephalopathy research. CTE is a diagnosis only made at autopsy.
"I thought a lot about it and even tried to contact people to make this donation," Silva said. "I have the most interested in donating, since I won't be using it anyway [laughs]. This area is very important.
"If I could leave a tip for the young guys, it would be don't hit yourselves every day," Silva added. "If you have a young student, don't let him take too many punches to the head. There's the right moment to do a hard training, but it can't be every day. A good coach takes care of your student."