Various Types of Hair Loss Have Different Average Rates of Loss
There are over 100 reasons to lose hair. Some of these reasons cause the hair density to be reduced extremely rapidly and other cause changes only slowly. It is extremely important when diagnosing hair loss to get a sense from the patient exactly how fast the hair is being loss. For example a patient with long standing androgenetic alopecia who was doing well in the past but now suddently starts losing more hair may have a second diagnosis that has entered the picture (such as a telogen effluvium). The chart here shows the most common of the hair loss conditions and the speed that they “typically” cause hair loss. There are of course exceptions.
Alopecia areata among the most rapid of hair loss types
The most rapid of all the forms of hair loss are alopecia areata and chemotherapy induced hair loss. These can cause complete hair loss in a matter of weeks in some people. Telogen effluvium never ever causes complete hair loss (and never in a matter of weeks) nor does androgenetic alopecia or scarring alopecia. The speed of hair loss is important. Some forms of male balding and some forms of scarring alopecia can be fast. In general though, they cause changes over many months (not weeks).
Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887