Anagen effluvium - Permanent hair loss caused by damage to hair folliclesTelogen effluvium - hair loss as a result of temporary damage to folliclesAnagen effluvium is generally due to internally administered medications, such as chemotherapy agents, that poison the growing hair follicle. Telogen effluvium is due to the increased number of hair follicles entering the resting stage. The most common causes of telogen effluvium are:Physical stress - surgery, illness, anemia, rapid weight changeEmotional stress - Mental illness, death in the familythyroid disordersMedications - High doses of vitamin A (sometimes present in dietary supplements), blood pressure medications, gout medicationHormonal Changes - Pregnancy, birth control pills, menopauseAndrogenetic Alopecia - Male / Female Pattern BaldnessUp to 95 percent of permanent hair loss due to androgenetic alopecia, a hereditary condition that affects millions of men, women and children