Nicknamed "the little lady with the big voice", Anastacia is known for her powerful soul voice, and her small stature – 5 feet 2 inches (157 cm). She was also known for her trademark glasses (often darkly tinted), but she had surgery to correct her vision permanently in August 2005. In 2005, she was recognized for worldwide sales of over 20 million records.
Anastacia was born in Chicago, Illinois; her late father Robert Newkirk (of German descent) was a club-singer and her mother Diane Hurley (of Irish descent) an actress on Broadway. After her father (a sufferer of bipolar disorder) left the Newkirk family, they moved to New York City when she was a teenager. Then she enrolled at the Professional Children's School in Manhattan.
Anastacia soon was diagnosed with Crohn's disease when she was thirteen. The incurable bowel disease led to an operation where surgeons cut directly through her stomach muscles removing a foot of the singer's intestines, causing Anastacia to be wheelchair bound and needing to learn how to walk again. Despite her illness she soon became interested in dance. However she was frequently critiqued for being 'too large to make it in the music business'. Anastacia subsequently dieted, triggering a Crohn's relapse that caused her intestines to collapse which resulted in hospitalisation tube feeding and steroid treatments which caused hair loss, weight gain and swelling of the face.