Etta James, pictured here in Los Angeles in 2008, is expected to be released soon from hospital, according to her son. (Matt Sayles/File/Associated Press)

Blues icon Etta James, who was under treatment for addiction to painkillers and other medications, is in hospital.

Her son Donto James has revealed his mother has been in hospital for a week, being treated for a blood infection. She is fighting the superbug known as MRSA — a bacterial infection resistant to many antibiotics — as well as other ailments.

James also revealed on CNN Friday night that his mother was diagnosed with Alzheimer's more than a year ago.

"Right now she is very confused," Donto James said on CNN, adding that she was very combative, too.

The four-time Grammy winner, best known for her 1961 song At Last, became ill while in a detoxification clinic, says her son.

James says he believes the hospital in Los Angeles will be discharging his mother "very soon." He also indicated the 72-year-old singer will not be going home but rather to a nursing home.

This isn't the first time James has suffered a critical illness. In 2007, she was hospitalized after having abdominal surgery a month earlier.

She was also in the headlines shortly after the inauguration of U.S. President Barack Obama in January 2009.

The performer lashed out at Beyonce Knowles, who portrayed James in a movie and was chosen to sing James's signature ballad At Last at the inaugural ball. James said: "I can't stand Beyonce."

Soon after, James made half-hearted retraction by telling the New York Daily News that, "Even as a little child, I've always had that comedian kind of attitude," indicating it was all in good fun.

Her son now says that it was his mother's Alzheimer's that caused the remark.

James has had a career spanning five decades, which included a suspended time during the 1960s in which she kicked a heroin habit.

Her hits include The Wallflower (Dance With Me, Henry), Good Rockin' Daddy, Pushover, Fool That I Am, Don't Cry Baby and I Just Wanna Make Love To You.

She was inducted into the U.S. Rock and Roll Hall of Fame in 1993.