The word effluvium means an outflow. Anagen effluvium is a condition in which people have their hair falling out during the anagen or growing phase of the hair growth cycle. The hair loss pattern is just like that of telogen effluvium in that the hair loss tends to be in a diffuse manner. At any given point, people should have 80-90% of their hair in the anagen phase, so if someone is suffering from anagen effluvium, they will suffer from a rapid type of hair loss since so many hairs will be affected. Anagen effluvium is usually caused by chemotherapy or radiation therapy.