Hair follicles normally emerge from the scalp in groups of 1, 2 or 3 haired "bundles." They don't all emerge as single strands.
During the process of genetic hair loss as well as during the process of scarring alopecias, the bundles of 2 and 3 haired follicular units start disappearing from the scalp and what is left is 1 and 2 haired follicular units.
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