Bruce Willis shares a hug with daughter Tallulah as they

Bruce Willis shares a hug with daughter Tallulah as they fool around amid his aphasia diagnosis

The world learned Wednesday that Hollywood legend Bruce Willis, 67, would be retiring following his diagnosis of aphasia, a potentially devastating condition that causes a person to lose their ability to communicate.

Willis’ family announced that the illness would cause the Die Hard star to “retire from the career that has meant so much to him.”

About a million Americans have the disease, reports the National Institutes of Health, and about 180,000 people are diagnosed with it each year.

It can manifest in a variety of ways and is often either the result of a head injury, stroke, tumor, or other damage to the brain.

Aphasia can also be devastating, with experts saying it causes depression in over a third of cases, can lead to personality changes and even alienate friends and family from the affected person.

Other famous examples of aphasia include former Arizona Congresswoman Gabby Giffords and Game of Thrones star Emilia Clarke.

“Imagine being dropped off in a country where you don’t speak the language – you can’t understand, read, write or speak. It would affect all your interactions – that’s what it’s like to have aphasia,” Darlene Williamson, president of the Aphasia Association, told .

While it’s impossible for Willis in particular to tell just how drastically the disease has affected him and his behavior, Williamson reports that it can often be devastating for patients.

“The consequences of living with a speech impairment can change a person’s behavior and outlook on life,” Williamson said.

“About 35 percent of people with aphasia experience depression.”

The cause of the condition, which is often some type of traumatic brain injury or stroke, can lead to massive personality changes.

‘[Aphasia is] Difficulties with speech resulting from brain injury. The most common cause is stroke… but it could be any other type of damage,” said Dr. Brenda Rapp, a cognitive scientist at Johns Hopkins University, told .

Certain infections that affect the brain’s language centers can also lead to the formation of aphasia, along with cognitive decline and deterioration associated with dementia.

The condition can make it very difficult for an actor like Willis to continue his career, as just pronouncing lines can become a challenge.

“It would certainly be difficult,” Williamson said of trying to continue acting while affected by the disease.

“Aphasia affects language comprehension, speaking, reading and writing. There are varying degrees of severity which would be another determining factor. It may not be impossible, but the acting would require additional adjustments.’

dr  Rapp said that despite communication failures caused by the disease, people suffering from the disease still have the same thoughts and are the same person inside.  While the experience can be alienating, loved ones should remember that the person has not changed.  Pictured: Willis with family and friends after a 'Roast' event in 2018

dr Rapp said that despite communication failures caused by the disease, people suffering from the disease still have the same thoughts and are the same person inside. While the experience can be alienating, loved ones should remember that the person has not changed. Pictured: Willis with family and friends after a ‘Roast’ event in 2018

There are four common types of aphasia that make up the vast majority of cases: fluent – often referred to as Wernicke syndrome; not fluent – known as Broca’s; anomic; and primary progressive aphasia.

Rapp explained that there are different forms of the condition, as each presents a different type of breakdown in the communication process.

Whether it’s the ability to translate thoughts into proper words, the ability to say words physically, or the ability to interpret and understand the language of others, every part of communication is a complex process, and even mild brain damage can cause problems.

While the condition causes communication errors, Rapp finds that the person himself is still the same.

Their thoughts, beliefs, and feelings about loved ones remain, even though dealing with the condition can be frustrating and alienating for both the aphasia sufferer and those around them.

Willis’ family did not disclose what type he was facing or how severe his case was or what was the root cause of the condition.

According to the Stroke Association, a UK-based group, those who suffer from Wernicke’s aphasia have the ability to string long phrases together, but often say things in ways that don’t make sense, or even use made-up words.

They also suffer from impaired literacy and may have difficulty understanding clear verbal communication with them.

An example used by Rapp is that a person can misinterpret the phrase “John kicked the dog.”

dr  Brenda Rapp, a cognitive scientist at Johns Hopkins University, explains that aphasia is often caused by a stroke and can manifest itself in many different ways

dr Brenda Rapp, a cognitive scientist at Johns Hopkins University, explains that aphasia is often caused by a stroke and can manifest itself in many different ways

While the average person in this scenario would clearly understand who kicked whom, a person dealing with this type of illness can have a hard time figuring out whether the person who kicked was John or the dog.

Broca’s aphasia often causes a person to forget words or piece together a correct sequence of words, even when their brain can fully understand what they are trying to say.

A person suffering from this type of illness often uses simple, short sentences to convey speech, as sometimes they cannot properly say what they want to say.

The Stroke Association says these sentences are often around four words or fewer.

A person suffering from Broca’s aphasia will also have difficulty writing, but their ability to read will remain unaffected.

Someone suffering from anomic aphasia may struggle to find specific verbs and nouns they need to get their point across and will speak very vaguely.

This can also carry over to their writing, where they simply won’t be able to generate the right words necessary to say what they want to say.

Primary Progressive Aphasia Aphasia damages a person’s ability to communicate in virtually every single way.

A person suffering from this version of the condition will have difficulty speaking, reading, and writing.

Their ability to process and understand someone speaking to them is also damaged.

Doctors can often detect aphasia through either an MRI or CT scan and pinpoint the exact part of the brain causing the problem.

There is no way to completely fix or cure the condition, but patients often undergo speech therapy to rebuild their language skills.

“There isn’t much progress [with medication for the condition]…the treatment for aphasia is speech therapy,” Rapp said.

She pointed out that in some cases, in addition to speech therapy, a person may undergo electrostimulation therapy to get the most out of the experience.

Williamson said that “strong family support is a crucial part of successfully living with aphasia.”

It’s not always permanent, however, and how long it lasts and how severe it is often depends on how severe the brain damage is.

Stroke patients in particular who suffer from aphasia can regain their speech, often within a few weeks.