Telogen Effluvium: Understanding the Hair Follicle Cycle and Hair Loss

The document from 2018 discussed the normal hair follicle cycle, which includes the anagen (growth) phase, catagen (transition) phase, and telogen (dormant) phase. It was noted that hair typically falls off during the later telogen or early anagen phase. On average, scalp follicles undergo 10-30 cycles in a lifetime, with hair replacement every 3-5 years. The document stated that about 86% of normal hair is in the anagen phase, 1% in catagen, and 13% in telogen. It was estimated that around 77 hairs are shed per day on average. The document indicated that disruption of this hair cycle and concurrent hair loss are signs of telogen effluvium.