Hair Evaluation Method: Pull Test and Wash Test

The document from 2015 discussed two noninvasive methods for diagnosing hair loss in women: the pull test and the wash test. The pull test involves pulling on the scalp hair in four different areas and counting the hairs that come out. Normally, only telogen hairs are shed, and their number should not exceed four to five for the whole scalp. The number and morphology of the hair roots can suggest the diagnosis of non-scarring or scarring alopecias. The wash test involves washing the hair after not shampooing for 5 days and counting the hairs collected on the basin floor. The total number of shed hairs indicates the severity of hair loss, with telogen effluvium indicated when more than 100 hairs are shed. The percentage of vellus hairs (those shorter than 3 cm) indicates the severity of androgenetic alopecia. These methods are simple, cheap, and useful in diagnosing hair loss.