Police are asking for help to trace 39-year-old Krishna Maya, who was last seen at her home address in Fleming Close at about 6pm yesterday (Sunday).
It is believed that the Nepalese national does not have her diabetes medication with her and officers are concerned for her welfare.
They were notified at 12.52am today and have since used sniffer dogs and a police helicopter to search the area - including local woodland.
Ms Maya (pictured) is described as Asian, with long black hair, brown eyes and about 5ft 6ins.
Inspector Greg Elphick, leading the investigation, said: "We are growing concerned for Krishna's welfare and would ask that anyone who has seen her or knows of her whereabouts call us as soon as possible."
Anyone with any information can contact the duty inspector at Loddon Valley police station via the 101 number.
To remain anonymous call Crimestoppers on 0800 555 111.