Lukhanyiso Lubelwana - who also goes by Lucky, Candice and Kelly Bowen - was last seen at Royal Lancaster Infirmary at around 11.25pm on Sunday (March 20).
The 35-year-old is also wanted on warrant for failing to appear at court in relation to two incidents of criminal damage.
"We are extremely concerned for her welfare and are asking anybody with information about where she may be to get in touch,” a spokesman for Lancashire Police said.
Lukhanyiso is described as slim, black and has short hair.
She was last seen wearing pearl hooped earrings, a pink coat, jeans and dark shoes.
She has links to the Ridge and city centre areas of Lancaster, as well as to Gloucester.
Anyone with information was asked not to approach but to call 101, quoting log number 1619 of March 20.
For immediate sightings, call 999.