Hair Loss Explained – Part 2
All About Hair
A primer on hair loss for Bellevue Seattle
hair restoration patients of The Stern Center
A typical Hair is made up of 4 key items:
The Hair shaft is the visible area of hair that you see on your head.
The Hair Follicle is the part of your skin that is responsible for growing hair.
The Hair Root is the part of your hair that is embedded in a hair follicle.
Dermal Papilla is the structure which contain receptors for male hormones that may contribute to hair loss.
Normal Hair Growth Cycle:
Normal hair growth is made up of this typical cycle:
During the “anagen” period, hair grows actively and reaches its maximum length within 2 to 6 years.
During the “catagen” period, which is a 2-4 week transitional phase in the normal hair growth cycle, hair breaks away from the dermal papilla and stops growing.
About 2 – 4 months later, during the “telogen” period, a new hair begins to grow and eventually pushes out the old hair.
It’s normal for everyone to lose hair during a typical hair growth cycle, and this “lost” hair is continually replaced by new hair. Any disruption to the normal hair growing cycle can lead to hair loss.
Baldness in Men
Typically, 10% to 15% of hair follicles are in the telogen (resting) phase. With the onset of male pattern hair loss, the number of hairs in this resting state can climb to over 20%. This shorter growth cycle means that hairs and being lost, more quickly than they are being produced.
Blame it on DHT
Men with male Pattern Hair Loss have increased levels of a hormone called dihydrotestosterone (DHT) in their scalps and an increased number of androgen receptors in thier dermal papillae. This makes the hair follicles more sensive to the effects of DHT.
Normal Cycle is Disrupted
When androgen receptors in the dermal papilla are exposed to DHT, a disruption of the normal hair growth cycle occurs which can lead to hair loss.
When Follicles are Exposed to DHT
As hair follicles are exposed to DHT, hair growth begins to slow and weaker, shorter hair is produced. The follicle exposed to DHT spends more time in the telogen (resting) phase and has a shorter anagen (growth) phase. The follicle actually shrinks and fails to grow.
Why Hair Restoration Procedures Work
By a man’s mid 30’s his body is no longer creating DHT. So once the patient’s hair is harvested and transplanted in the preferred recepient site, the hair will begin to grow (in as little as 5-6 months, but could be as long as 12 months), and will continue to grow without any worries about renewed DHT activity.