iAremyhair believes in giving our customers ample information so that they can make wise decisions regarding hair loss treatment.
For this purpose, we will be introducing a series of topics that offer insight and objective viewpoints. Topics range from basics of hair to hair loss causes to treatment options to other related and interesting issues.
To ensure that our readers get the most out of our newsletters, we have condensed information from established publications and online reference materials such that each topic can be easily digested. iAremyhair invites you on this journey and welcomes your comments.
When are you 'officially' defined as having hair loss and what causes it? Some people panic when they see ten strands in the bathroom after showering. Others don't notice until a coin size bald patch actually appears. When it comes to the causes, some people simply blame it on genes and others come up with other theories.
Actually, as part of the hair renewal process, it is normal to shed between 50 to 100 hairs a day but when it gets excessive, you may be experiencing the most common type of hair loss known as androgenetic alopecia, also known as male pattern hair loss. It is an inherited condition that affects both men and women although it is more common among the men.
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Statistic Up to 98% of men with balding fall into the genetic category. Female genetic balding occurs much less frequently, but up to 50% of women have hair loss related to their inherited genes.(Hair Loss & Replacement for Dummies. Rassman & Bernstein) |
Genetically programmed hair follicles
In individuals with androgenetic alopecia, certain hair follicles are genetically programmed to be more sensitive to a hormone called dihydrotestosterone (DHT) circulating in the blood. DHT is an androgen, often referred to as the "male" hormone. While men have higher levels of androgen hormones in their blood, it is normal for women to have some androgens. DHT binds to receptive follicles to cause the specific changes associated with balding. In other words, DHT in the blood has the ability to signal these hair follicles to stop growing new hairs.
androgenetic alopecia = a genetic predisposition + the presence of androgens
http://www.highbeam.com/doc/1G1-20220939.html
For the men, the DHT-sensitive hair follicles are generally located at the temples, the hairline and on the crown of the head. For the women, these follicles are distributed over a wider area and thus, a generalised thinning over the entire top of the head. Why are some areas of the scalp not affected? It is because there are some hair follicles that are not receptive to the hormone DHT and these follicles are able to grow new hairs for a lifetime. Thus, DHT by itself is not the cause of hair loss; the question is how many of our hair follicles have been genetically programmed to be receptive to DHT?
The effects of DHT on DHT-sensitive hair follicles
Hair follicles sensitive to DHT must be exposed to a high enough level of DHT in the blood over a long period of time before they get the message to start shutting down. And the message has to continue for years before a hair follicle completely stops producing new hairs. Thus, an early examination is necessary for an effective cure. Most people discover their hair loss only towards the later stages or choose to do something about it only later.
Normal hair follicles go through a growth cycle of roughly four to six years but DHT-sensitive follicles have shorter anagen (growth) phases. Instead of four to six years, the growth cycle shortens to three to four years, and then one to two years and eventually these hair follicles stop producing new hairs and stay in the telogen (resting) phase.
Scalp hairs grow approximately one-half inch per month which works out to six inches per year. If the growth phase of a follicle is six years, the hair grown by that follicle could reach thirty-six inches in length but if the growth phase is shortened to two years, the maximum length of the hair would be only twelve inches when it is shed. Thus, one may notice that some hairs that have fallen are shorter than one's normal hair length.
It is believed that each hair follicle is genetically programmed for a limited number of growth cycles. The shorter the duration of each cycle, the sooner a particular hair follicle goes through all of its growth cycles and stops producing new hair. For example, if a particular hair follicle is programmed to have twenty complete growth cycles, each lasting an average of four years, then that hair follicle will continue to produce hairs for 80 years. But for hair follicles programmed with, say, fifteen growth cycles and each lasting only two years, then the person in question is likely to face baldness before thirty years of age.
Apart from disrupting the normal growth phase of DHT-sensitive hair follicles, DHT shrinks these follicles. There is evidence that with each successive growth cycle, these hair follicles become miniaturized (smaller) and the hairs produced by these follicles will be thinner and less pigmented.
What does it mean for hair loss sufferers?
It seems daunting to combat hair loss due to genetics and the hormone DHT but it is not impossible. To date the most effective preventative treatments are anti androgens, drugs that prevent the creation of DHT. In the future, gene therapy will one day be able to alter the genes to prevent the follicles from being affected by DHT.
Stayed tuned for our next issue
where we will talk about other hair loss causes
which are no less important.
Reference Materials
Panagotacos, Peter J, M.D. "Hair Loss Answers". USA : Author's Publishing Cooperative, 2005.
http://www.hairlosshelp.com/hair_loss_research/hairloss_causes.cfm
