Sam Humphrey is to undergo ''high risk'' surgery.

The 'Greatest Showman' actor - who suffers from skeletal dysplasia and stands at 4ft 2in and- is set to go under the knife in Los Angeles after suffering from Crohn's disease complications and his loved ones have appealed for privacy over the coming weeks.

His family said in a statement to E! News: ''Sam has been suffering from complications due to Crohn's disease, which is exasperated by Sam's skeletal dysplasia and size.

''He is currently under the care of some of the best doctors in the world at Cedars Sinai and is undergoing high-risk corrective surgery. His family and friends are with him and they ask for privacy while Sam is treated and recovers.

''They welcome everyone's prayers and support at this time.''

Shortly before the news was announced, the 24-year-old star took to his Instagram account to wish his 'Greatest Showman' co-star Zendaya a happy birthday.

He shared a photo of them together and wrote: ''To a really amazing beautiful gal.

''She's super talented and a huge super star; what an incredible experience and honor to work alongside such a talented talented young artist!!HAPPY BIRTHDAY ZENDAYA.(sic)''

Sam has previously spoken about how he had wanted to be an actor since he was a child and cited 'Greatest Showman' co-star Hugh Jackman as his inspiration.

He previously said: ''I've always wanted to become an actor since the age of five. Lots of kids wanted to grow up to be a fireman or anybody else.

''It was when I was eight years old, I saw Hugh on the big screen for the first time. I really enjoyed his performance. Something just triggered inside me and knew that was the guy I wanted to follow as an actor and for my career. Ever since then, he was my inspiration in acting.''