Hair loss can be assessed objectively by examining a hair pull sample for stage of growth and hair shaft diameter, getting an estimate of average daily hair loss, and mapping scalp hair density. The history of the loss, the clinical picture, and the growth stage and diameter of the hair when lost all help to establish the type of loss. Hair regrowth occurs without treatment in most types of hair loss. There is as yet no effective treatment for pattern or senescent alopecia, although in women the loss can now be retarded somewhat.