The family of US actor Bruce Willis have announced that he is stepping back from his successful acting career after being diagnosed with aphasia.

Disclosing the news on social media, his family said it had been a “really challenging time” for them and thanked fans for their “continued love, compassion and support”.

Here’s everything you need to know about the condition…

What is aphasia?

Aphasia is a disorder caused by damage in a specific area of the brain that controls language expression and comprehension, according to John Hopkins University of Medicine.

The condition leaves a person unable to communicate effectively with others, and Willis’ family said his aphasia had been “impacting his cognitive abilities”.

What causes aphasia?

The damage caused by aphasia may be brought on by several things including a stroke, head injury, brain tumour, infection or dementia.

According to the NHS, the condition can affect people of all ages, though it is more common in people over the age of 65 – when strokes and progressive neurological conditions are more likely.

The family did not specify further details about Willis’ condition or what had caused it.

The actor is 67.

What are the symptoms of aphasia?

Aphasia can affect different people in different ways, though common symptoms involve difficulty with the main forms of communications; reading, writing, speaking and listening.

Speaking problems are most obvious and those with the condition may make mistakes with the words they use, according to the NHS.

This can manifest in using the wrong sounds in words, choosing the wrong word, or putting words together incorrectly in a sentence.

The NHS says that although aphasia affects a person’s ability to communicate, it does not affect their intelligence.

How is aphasia treated?

As with symptoms, treatment for aphasia varies from person to person.

Factors affecting treatments will include an individual’s age, overall health, medical history and the severity of the condition.

The most common, practical treatments are speech and language therapy to help restore some of the ability to communicate, though it may also be necessary to develop alternate ways to communicate.

According to the NHS, most people make some degree of recovery from aphasia, though this is more likely if it has been caused by a one-off event such as a stroke.

The chances of recovery are poorer if aphasia has resulted from a progressive neurological condition.