Billy Joel's daughter is speaking out in support of her father following his recent health diagnosis. Alexa Ray Joel - the daughter of the "Piano Man" and his ex-wife, model Christie Brinkley - took to social media on Sunday (May 25) to thank fans for their support and share an uplifting message after her father revealed he had been diagnosed with normal pressure hydrocephalus (NPH),

Last week, the 76-year-old musician announced that he was diagnosed with the rare brain condition and had to cancel the remainder of his tour.

Christie Brinkley is showing support for her ex-husband Billy Joel following news of his recent brain diagnosis. The supermodel, who shares daughter Alexa Ray with the legendary singer, posted a video on Instagram Saturday -- just one day after Joel revealed he had been diagnosed with normal pressure hydrocephalus.