Former US first lady Barbara Bush, 92, seriously ill with lung disease and heart failure

A file picture from March 29, 2015, shows former US President George H.W. Bush and his wife Barbara Bush, left, at a college basketball match in Houston. Photo / AP

Former US first lady Barbara Bush is seriously ill and no longer wants to seek medical treatment.

The 92-year-old wife of US President George H. W. Bush is being cared for at her home in Houston, Texas after deciding she does not want to remain in hospital.

Bush has been in and out of hospital recently and is now in "failing health", according to a family spokesman.

"Following a recent series of hospitalisations, and after consulting her family and doctors, Mrs Bush, now age 92, has decided not to seek additional medical treatment and will instead focus on comfort care," the statement said.

"It will not surprise those who know her that Barbara Bush has been a rock in the face of her failing health, worrying not for herself - thanks to her abiding faith - but for others.

"She is surrounded by a family she adores, and appreciates the many kind messages and especially the prayers she is receiving."

The former first lady has been battling chronic obstructive pulmonary disease and congestive heart failure, a source close to the family told CNN.

The Bushes have been married since 1945.

Barbara is the mother of former President George W. Bush and former Florida Governor Jeb Bush.