Emergency services were called to Old Street, Clydebank, at around 6.20am yesterday and found the woman on the pavement.
She did not appear to be injured and had no handbag or purse.
She was taken to the Western Infirmary in Glasgow.
Strathclyde Police are appealed for help to identify the woman.
She is in her late 40s or early 50s, about 5ft 6in tall and of medium to stocky build, with straight brown or auburn shoulder-length hair.
She was wearing a purple Hi-Gear waterproof jacket, a blue and white blouse and black leggings and shoes.
Her watch has a white leather strap and she is wearing a gold ring.