Physiology of Hair Growth
Hair grows in three phases: anagen (active growing, about 90 % of hairs), catagen (degeneration, less than 10% of hairs) and telogen (resting, 5% to 10% of hairs). Hair is shed during the telogen phase.
Am Fam Physician. 2017;96(6):371-378. © 2017 American Academy of Family Physicians