Bruce Willis stepping away from acting following aphasia diagnosis

Willis' family said he was recently "diagnosed with aphasia, which is impacting his cognitive abilities."

He loss of ability to understand or express speech, his family said in a statement posted to social media.

Aphasia describes a neurological condition that affects a person’s ability to communicate verbally or through writing.

Willis' daughter Rumer Willis posted Wednesday on Instagram that the condition has affected her father's "cognitive abilities."

It can also arise as a result of a head injury, a brain tumor, an infection or a degenerative disease like Alzheimer's.

Medical experts say the impacts of aphasia can vary, depending on the person's diagnosis.

Willis, an Emmy-winning actor and the star of hit movies like "Die Hard" and "The Sixth Sense," turned 67 this month.

Willis ans were sharing their disbelief and sadness over the development.