Hair Loss
Contrary to popular belief, clogged pores, wearing hats, and unhealthy hair shafts are not the cause hair loss. Generally, most people experience hair loss due to a genetic disposition (heredity). Inherited hair loss, known medically as androgenetic alopecia, is the most prevalent type of hair loss in each sex. Commonly referred to as ‘male pattern baldness’ and ‘common female hair loss,' androgenetic alopecia results from a follicle’s genetically determined sensitivity to hormones, such as dihydrotestosterone (DHT). Such hormones cause sensitive follicles to shrink, over time affecting the hair shaft leading to thinning and ultimately to permanent hair loss. Other factors of hair loss are more temporary, such as stress, illness, nutrient deficiency, and the use of certain drugs.
Generally speaking, male pattern baldness can be expected to occur in 25% of men aged 25-30, 40% of men aged 40, and 50% of men aged 50 or more. The onset of male pattern baldness can be at any time after puberty and, contrary to popular belief, it not infrequently begins in the late teens.
Women generally experience more generalized hair loss. This is also genetic in origin. New techniques allow us to perform transplant surgery on a greater number of women who were not candidates with older technology. For more in-depth information on hair loss for women, click on the link to the left.
The Hair Cycle
All hair follicles go through a normal cycle of hair growth and hair loss. There are three main phases of the hair growth cycle: anagen, catagen, and telogen.
During the anagen phase hair fibers are actively produced from the dermal papilla, a highly active group of pear-shaped cells within the follicle. The longest of the three phases, anagen lasts anywhere between 6 to 10 years, with an average growth rate of 1/2 inch per month.
During the catagen phase, which is estimated to last approximately 14 to 21 days, hair growth enters a period of regression; the dermal papilla condense as the cells become inactive. With a lack of cell stimulation, the hair fiber and root sheaths stop growing.
Lastly, the follicle enters a period of rest for anywhere between 30 to 90 days. In telogen the dermal papilla can become isolated and the hair fiber can be easily pulled out from everyday activites such as combing, shampooing, or brushing. At any given time, approximately 10% of hair follicles on the scalp are in telogen, which means each day an average of 50 to 100 hairs are pulled out.
While this cycle of hair production typically continues for the duration of the individual's life, as explained earlier, there are follicles with a genetic disposition to permanent hair loss. Other factors that may effect hair growth include: adverse reactions to drugs or medical treatments, hormones, as well as immune system abnormalities.