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There’s a particular kind of panic that sets in when you realize your ponytail feels thinner. It’s usually subtle at first: Noticing a wider part, more strands in the shower drain, or perhaps that you might benefit from some root touch-up powder. And while hair trends aim to embrace every texture and length, thinning hair is still something most women whisper about, but the best hair growth serums can make all the difference…….Continue reading…
By Deena Campbell
Source: Bazaar
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Critics:
Alopecia is a hair loss disease that can occur in anyone at any stage of life. Specifically alopecia areata is an autoimmune disease that causes hair to spontaneously fall out. It is mainly characterized by bald patches on the scalp or other parts of the body, and can ultimately cause baldness across the entire body. This disease interferes with the hair growth cycle by causing a follicle to prematurely leave the anagen, or active growth, phase and enter the resting, or telogen, phase.
The hair growth in the affected follicles is lessened or stopped completely. Primary Cicatricial Alopecias (PCAs), commonly referred to as scarring alopecias, are a collective group of inflammatory disorders with distinctive pathological features that include the development of fibrosis, permanent destruction of the pilosebaceous unit of the hair follicle (HF), and irreversible hair loss.
Traction alopecia is caused by adding too much strain on the hair on one’s head. Tight ponytails and other styles that require added tension to the hair are often what cause this disease. It can also occur on the face in areas where the hair is often styled. Plucking or waxing one’s eyebrows frequently, for example, can yield suppressed hair growth in the area.
On the scalp, the hair is usually known to be lost around the hair line, leaving the densest amount of hair at the crown. Small vellus hair will often replace the hair that is lost. Human hair follicles are very sensitive to the effects of radiation therapy administered to the head, most commonly used to treat cancerous growths within the brain. Hair shedding may start as soon as two weeks after the first dose of radiation and will continue for a couple of weeks.
Hair follicles typically enter the telogen phase, and regrowth should commence 2.5 to 3 months after the hair begins to shed. Regrowth may be sparser after treatment.The anagen phase, known as the growth phase, is when the hair grows about 1 cm per month. It begins in the papilla and can last from three to five years. The span at which the hair remains in this stage of growth is determined by genetics. The longer the hair stays in the anagen phase, the longer it will grow.
During this phase, cells neighboring the papilla in a germinative layer divide to produce new hair fibers, and the follicle buries itself into the dermal layer of the skin to nourish the strand. About 85%–90% of the hairs on one’s head are in the anagen phase at any given time. The catagen phase, or the transitional phase, allows the follicle to renew itself (in a sense). During this time, which lasts about two weeks, the hair follicle shrinks due to disintegration and the papilla detaches and “rests,” cutting the hair strand off from its nourishing blood supply.
Signals sent out by the body (that only selectively affect 1 percent of all hair of one’s body at any given time) determine the end of melanin production in the hair bulb and apoptosis of follicular melanocytes. Ultimately, the follicle is 1/6 its original length, causing the hair shaft to be pushed upward. The telogen (resting) phase of the hair follicle lasts about three months. The final product of a hair follicle in the telogen stage is a dead, fully keratinized hair (a “club hair”).
A normal scalp sheds 50-100 such hairs per day. When the body is subjected to extreme stress, as much as 70% of hair can enter the telogen phase at the same time and begin to fall out (“telogen effluvium”).
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