The singer-actress voluntarily entered the Promises center in Malibu about 10 days ago "to clear up some personal issues," Paul Bloch said.
"She wants to be in great shape because she is someone who feels a sense of responsibility to her family and her fans," he said, reading from a prepared statement.
Bloch said he did not know when Ross would be released or the specific problem for which she was receiving treatment.
Ross, 58, was scheduled to begin her tour on June 26 in Germany. Bloch said the performances would not be postponed.
"She'll be touring," he said. "She'll be doing the great show she always does."
According to Hollywood.com Ross graduated from lead singer of the most famous girl group in showbiz, The Supremes, to a solo act combining coy, feline sexuality with slick packaging.
Although movie stardom has so far eluded her, she did earn an oscar nomination for her film debut in the Billie Holliday story, "Lady Sings The Blues."
She was also nominated for an Emmy award for her role as a paranoid schizophrenic in the television movie "Out of Darkness" in 1994.
A child of the Detroit projects, by her late teens, Ross was singing in a quintet called "The Primettes." In 1961, the group was just a trio — Ross, Mary Wilson and Florence Ballard — and was renamed "The Supremes" and signed by Motown's star-maker, Berry Gordy Jr. Ross left the group in 1971, although she attempted an ill-fated comeback tour two years ago with two other women.
Wilson and Cindy Birdsong, who performed with Ross in the Supremes in the 1960s, refused to join the 2000 tour because they felt they weren't being paid enough. Instead, Ross worked with Lynda Laurence and Scherrie Payne, who had joined the Supremes after she had left in 1969. Ticket sales were poor, and after 12 cities, the tour was canceled.
According to Hollywood.com, anthologies of her many hits, with and without the Supremes, have sold well, and she continues to produce a hit song every few years.