Within the hair regeneration cycle, hair loss occurs to make room for the new hair. The average person loses about 25 to 100 hairs normally each day. However, in more serious hair loss conditions, excess hair shedding occurs, causing more and more hair to fall out over time. Today, we will look at what happens during the hair regeneration cycle to cause hair loss and thinning.
As we have previously discussed, the hair regeneration cycle takes hair through a process of growth, loss and regrowth. Hair growth occurs in three phases: anagen, catagen and telogen. New hair growth occurs in the anagen phase, hair transitions in the catagen, and in the telogen phase, hair rests and makes room for new hair. With the last phase, some hair shedding is common.
However, in conditions relating to hair loss, this cycle of regeneration slows down and changes, causing more hair loss and less regrowth over time. Depending on the condition, the hair regeneration cycle begins to slow down and may eventually stop altogether.
Several conditions and factors can cause hair shedding, thinning and loss. Medical disorders, medication, poor nutrition, bad hair care techniques, stress and heredity can all cause hair loss.
Hereditary hair loss, or androgenetic alopecia, causes problems within the hair growth cycle. Over time, the genes and hormones in your body shrink your hair follicle, making it harder from hair to progress through the growth cycle. Progressive shrinking of scalp follicles short the length of the hair’s growth cycle, slowing down the process. As the follicles shrink, hair becomes thinner and shorter. Eventually, the hair growth cycle grinds to a halt and no hair growth occurs at all. With no growth occurring and the follicle shrinking, remaining hair is pushed out. In 95 percent of cases, hair loss is the cause of androgenetic alopecia.
Telogen Effluvium is the second most common form of hair loss. Telogen Effluvium is linked to traumatic body experiences such as childbirth, malnutrition, severe infection, major surgery or extreme stress. In cases of Telogen Effluvium, many of the hairs in the anagen (growing) or catagen (resting) phase suddenly shift into the shedding (telogen) phase. With 90 percent of all hair being in the anagen or catagen phase, large amounts of hair can be lost during the shift, but for most, this condition does not cause total hair loss. In the majority of cases, this condition can be fully reversible as the hair follicles are not permanent or irreversibly affected. This condition affects women more often than men, due to its link to childbirth.
Anagen effluvium is the result of any insult to the hair follicle that impairs its cellular activity. As a result of damage to the matrix- where hair cells multiply and differentiate, the hair shafts rapidly narrow during anagen effluvium. Eventually, the hair shaft will fracture at the site of the narrowing, causing hair to shed. This condition is most commonly associated with cancer treatments, such as chemotherapy and radiotherapy. Since these substances inhibit rapid cell division, the rapidly dividing hair cells are often attacked. As a result, the hair fiber production is completely frozen and shut down. This condition is very rapid and can cause complete hair loss. However, anagen effluvium is totally reversible and recovery is equally as rapid.