On Wednesday, the family of action star Bruce Willis announced that the actor, causing him to step away from his career at the age of 67. Aphasia is medical condition that leaves patients struggling to understand language and communicate.
According to Mayo Clinic, aphasia can begin as trouble communicating. Someone with aphasia might have trouble finding the correct words, substitute the wrong words for each other or speak in short sentences that are difficult or impossible to understand. These issues are related to brain damage in the left side of the brain, which controls language, Johns Hopkins explains.
While its presentations can vary, aphasia is usually a symptom of a broader medical issue. It may result from a stroke, head injury or tumor, or develop due to a degenerative brain condition.
While potential drug therapies are being tested, the current treatment options are limited. Patients may undergo language and speech rehabilitation, which are focused on restoring as much language as possible, and finding other ways to communicate in order to replace language that is lost for good.
"Recovery of language skills is usually a relatively slow process," Mayo Clinic says. "Although most people make significant progress, few people regain full pre-injury communication levels."
In an Instagram post, Willis' family wrote that the condition "is impacting his cognitive abilities," but experts say aphasia is more accurately described as a language disorder than a cognitive illness.
"This is a really challenging time for our family and we are so appreciative of your continued love, compassion and support," Willis' family said in a statement. "We are moving through this as a strong family unit, and wanted to bring his fans in because we know how much he means to you, as you do to him."
Willis is best known for his starring role as John McClane in the "Die Hard" action franchise. He has appeared in dozens of films over a more than 40-year career, including "12 Monkey," "Moonrise Kingdom" and "Pulp Fiction," and the popular 1980s TV series "Moonlighting."
This story has been updated.