There are two different types of hair loss, medically known as anagen effluvium and Telogen effluvium. Anagen effluvium is generally due to internally administered medications, such as chemotherapy agents, that poison the growing hair follicle Telogen effluvium, is due to an increased number of hair follicles entering the resting stage.

The most common causes of telogen effluvium are:

• Physical stress: surgery, illness, anemia, rapid weight change.
• Emotional stress: mental illness, death of a family member.
• Thyroid abnormalities.
• Medications: High does of Vitamin A -- Blood pressure medications -- Gout medications.
• Hormonal causes: pregnancy, birth control pills, menopause.

  Causes of temporary hair loss include:

When the above causes of telogen effluvium are reversed or altered you should see the return of normal hair growth.

The typical pattern of female-pattern baldness is different than that of male pattern baldness. The hair thins all over the head, but the frontal hairline is maintained. There may be a moderate loss of hair on the crown, but this rarely progresses to total or near baldness as it may in men.

Hair loss can occur in women for reasons other than female-pattern baldness. These may include temporary shedding of hair (telogen effluvium), breaking of hair (from such things as styling treatments, and twisting or pulling of hair), patchy areas of total hair loss (alopecia areata--an immune disorder causing temporary hair loss), oral medications, as well as certain skin diseases.

The hair loss of female-pattern baldness is permanent. The hair loss is usually mild to moderate. No treatment is required if the person is comfortable with her appearance.

The only drug or medication approved by the United States Food and Drug Administration (FDA) to treat female-pattern baldness is minoxidil, used topically on the scalp. It may help hair to grow in 40% of the population, and in 90% it may slow the loss of hair. Hair loss recurs when its use is stopped.