Sarah Hyland has wished her younger brother a ''Happy Kidneyversary''.

The 'Modern Family' actress underwent a kidney transplant two years ago, with Ian Hyland donating his organ, and she's paid tribute to her ''precious'' sibling for saving her life thanks to the procedure.

Sarah - who was born with kidney dysplasia, a condition meaning the organs didn't fully develop - wrote on Instagram: ''2 years ago today my precious little brother gave me the gift of life.

''Thank you for not only giving me your f***ing kidney but for everything else you do.

''I love you so much @thehotterhyland [heart emoji] happy Kidneyversary!!!! (sic)''

Ian, 24, sent similar wishes to his 28-year-old sister - who got engaged to partner Wells Adams in July - and admitted he felt ''proud'' to be her brother.

He wrote: ''Happy Kidneyversary to an incredible older sister and all-around badass.

''I am so happy that you are living your dreams and have such an incredible year and life ahead of you. You make me so proud to be your brother. I love you, sis!''

Sarah recently admitted she thinks her chronic illness has helped make her ''stronger''.

She said: ''Everything happens for a reason. [Struggles are] only going to make you a stronger and more efficient person.''

And although her outlook it positive, Sarah notes that she wasn't always so upbeat about her illness.

In 2012, Sarah underwent her first kidney transplant when her father donated his kidney, but four years later she found out her body was rejecting the organ, which left her feeling ''guilty''.

She added: ''When I found out, there was a nice cocktail of guilt, fear and a kind of hopelessness. But also it was like, okay, this is now a part of your life.''