Police are investigating a road traffic collision which occurred at Rigmaden near Middleton at approx 9:40pm on Saturday 11 May.
A Cumbria Police spokesman said: “A woman, aged in her 20s was taken to the Royal Preston Hospital with serious injuries after falling from a vehicle.
“She remains in hospital and her condition is described as critical.
“The 22-year-old driver of an Audi A3 from Brampton is helping police with their enquiries.”
Anyone with information is asked to contact PC Walsh at Kendal Mobile Support Group on 101 quoting log 248 of 11 May.