Telogen effluvium. Telogen effluvium (TE) is the thinning of hair due to stress. Why it occurs is not really understood. Telogen is the name for the resting stage of the hair growth cycle and TE causes the actively growing hairs to cycle into the resting stage and fall out. This means a decrease in the number of hair follicles producing hair, causing a thinning.
Medically Reviewed by Stephanie S. Gardner, MD on April 26, 2022