The daughter of the music legend Nat King Cole was admitted to a New York City hospital after she suffered a setback stemming from her harsh chemotherapy treatment for hepatitis C. She was first diagnosed with the illness last spring, but only went public a few months later, in July, and she has been struggling ever since with the painful treatment.

Natalie Cole revealed her hectic life-style and drug abuse in her 2000 memoir, “Angel on My Shoulder” and admits that her disease is a direct result of heavy heroin addiction in her youth, as well as other recreational drugs that she says she started using while attending the University of Massachusetts at Amherst. Among the illegal substances Cole writes about in her book are LSD, heroin and crack cocaine and it seems like she was a constant consumer, until she eventually entered rehab in 1983.

The recent hospitalization has forced her to call off several in-store appearances, including one scheduled Thursday at a Borders store in Los Angeles, along with a concert tour that was to start October 3 in support of the “Still Unforgettable” album, which was released last week and debuted at No. 19 on the album charts.

Although she was responding very well to her treatment when she first started, the combination of side effects from chemo, which include nausea, dehydration and fatigue, with a hectic schedule of promotional appearances and concerts for her new record have forced Natalie to take some time off and take care of her health.

“The combination of the treatment she’s been undergoing and the heavy promotional schedule for her new album took its toll,” Cole's publicist Maureen O’Connor said. “Her doctors decided they needed to put her in the hospital. They expect her to be there for a few days, then she’ll be on a month of bed rest.”

Natalie also gave a statement for her disappointed, yet supporting fans: “I wanted to express my sincerest apologies as I was excited to greet my fans tonight, but my illness got the best of me. I look forward to seeing you all very soon.”

Natalie Cole’s career and life have been up and down ever since she first started to perform, at only 11, as she was being raised in a deeply musical and cultural atmosphere. Her famous father, Nat King Cole, was a great influence, although he died of lung cancer when she was only 15.

For many years, the young Cole wanted to make a name of her own and her 1975 debut album, “Inseparable,” resulted in chart success with the single "This Will Be (An Everlasting Love)" and also brought her a 1976 Grammy for Best Female R&B Vocal Performance, managing to break Aretha Franklin’s string of 8 awards in this category.

She released several other hits, like "Sophisticated Lady (She's A Different Lady), (1976), "Someone That I Used To Love" (1980), as well as 1977's "I've Got Love On My Mind" and "Our Love," but her greatest moment was when she finally embraced her father’s heritage on her 1991 album, “Unforgettable... with Love.” It sold over 7 million copies in the United States alone, and won Cole several Grammy Awards, including Album of the Year, Record of the Year, and Best Traditional Pop Vocal Performance and made the famous duet with her father an all-time classic.