Is Hair Loss Normal in the Hair Growth Cycle? – DrFormulas

Is Hair Loss Normal in the Hair Growth Cycle?

Is Hair Loss Normal in the Hair Growth Cycle?

Hair loss, also called alopecia, can be a problem for people of all ages, sexes and ethnicity.

Hair, composed of keratin[1], sits firmly in a hair follicle, which houses the hair bulb. The hair bulb acts as the "root" of the hair and serves as the place where cells divide to grow the hair shaft.

What is the Normal Hair Growth Cycle?

On the human scalp, hair grows at about .4 mm/day, or 6" per year[2]. While human hair grows in phases, the growth pattern is not cyclical. Instead, random hairs can be in one of the following three growth phases at any time:

Is Hair Loss Normal in the Hair Growth Cycle?

Anagen

The Anagen phase is the growing phase of the hair. During this time, new hair is forming and pushing out of the follicle. Hair grows about 1 cm. in 28 days during this phase. At any time 90% of hair is in anagen. Rapid loss during this phase is called anagen effluvium and commonly occurs in people taking chemotherapy drugs or people who are exposed cytotoxic drugs that prevent cellular replication like rat poison. This results in a rapid shutdown of hair production.

Catagen 

The Catagen phase is the end of active hair growth and is a transitional phase and about <1% of the head's total hair follicles are in this phase at a given point. During this phase, which lasts about 2-3 weeks, growth stops and the fully formed and keratinized club hair forms.

Telogen

The Telogen phase is a resting phase. About 10% of hair follicles are in it at any given time. This phase lasts about 100 days for scalp follicles and longer for hairs on other parts of the body. In the Telogen phase, club hair formation is complete and the follicle is at rest.

    Diffuse Hair Shedding Throughout the Scalp

    Hair shedding of about 100 hairs per day is normal and happens to hairs in the telogen phase. Activities like brushing the hair and showering cause normal hair shedding.  Once a hair has been shed, it can take about 6-8 months [3] for hair to grow back.

    However, high-stress situations, pregnancy, deficiency in nutrients and vitamins, DHT imbalance, and illness can exacerbate hair shedding. Hair shedding in excess of 100 hairs per day throughout the scalp is called telogen effluvium and is usually caused by stress or some other sudden acute change. This means that instead of 10% of hair follicles being in the telogen phase at one time, up to 35% could be in the telogen, or resting, phase. The hair loss in telogen effluvium is diffuse and affects all areas of all hairs throughout the scalp.

    Pattern Hair Shedding

    Hair loss that follows a distinctive pattern – affecting the front hair line and the top of the scalp is called androgenetic alopecia. This is more commonly known as male pattern baldness in men and female pattern baldness in women. Hair loss following this pattern will require a doctor’s visit to diagnose and is usually treated with over the counter minoxidil in women and men. Sometimes men are also prescribed low dose finasteride (Propecia®) for male pattern baldness.

    Hair Breakage

    Hair shedding and hair breakage are not the same. Hair shedding means losing a complete hair, while breakage involves the hair shaft snapping. To see if your thinning hair is due to hair loss or breakage simply look at the hairs collected in your brush; if the root is still attached (the white bulb that clients often mistake for dandruff or product buildup), you’re losing hair. If the ends are frayed or look chewed, this is most certainly breakage and should be addressed. Both conditions are normal, except in excess. 

    Excessive hair breakage is usually by weak and brittle hair due to a lack of proper hair care which includes: over-treatment, neglect, excessive application of product, and tension on hair in the form of braids or other hair designs, and poor nutrition.

    It can also be caused by a fungal infection and result in a condition called tinea captitis. Therefore, it is important to see your doctor if you have excessive scalp itching or redness associated with inflammation and infection.

    Is Hair Loss Normal?

    Hair loss up to 100 strands of hair a day is normal. Hair loss exceeding about 100 strands per day[4] is likely to be telogen effluvium (TE)[5] -- a condition in which hair has been pushed into the regression phase. TE can be caused by medication changes and stressors such as major life changes. Stressing about the hair loss can make things worse. Removal of stressors, treatment of the underlying cause, and relaxation techniques can help.

    Hair loss following a pattern that affects the front hair line and the top of the scalp is called androgentic alopecia and affects both men and women. It requires a doctor’s visit for definitive diagnosis is usually treated with over the counter minoxidil and/or low dose finasteride in men.

    Hair breakage is not normal and is usually a sign of dietary deficiencies or fungal infection. When dietary deficiencies are suspected, supplements containing at the very least biotin may be taken. However, supplements themselves can cause problems. For example, taking too much vitamin A can cause hair loss. It is important that the supplements you take are carefully formulated and that when you take multiple supplements you add the daily values together to make sure that you are not taking too much of one.

    Here is a quick summary of major causes of hair loss and their treatments. This is by no means an exclusive list.

     

     

     

    Pattern

    Causes

    Treatment

    Telogen effluvium (TE)

    Diffuse, throughout the scalp, loss > 100 strands per day

    Stress (life events, surgery), Rapid weight loss, Dietary deficiencies, Recent childbirth or miscarriage, iron deficiency anemia, or thyroid disorder, toxin exposure

    Treat underlying cause(s): Remove stressors, remove offending medication, take dietary supplements for nutrient deficiencies, treat thyroid problems

    Hair Breakage

    Hair breaks mid-shaft, does not affect the root or bulb of hair

    Over treatment, traction, poor nutrition, tangled, curly hair

    Avoid chemical treatment of hair, avoid putting traction on and braiding hair, dietary supplements. Untangle hair carefully and with a wide toothed comb.

    Androgentic Alopecia

    Front of Hairline and very top of the scalp

    Genetics, dihydrotestosterone

    Minoxidil, Finasteride in men

     

     

     

    FAQ's Answered in This Article: 

    What is the cycle of hair growth?

    How long is the shedding phase of hair? What is normal?

    How long does it take for new hair to grow?

    What is the difference between hair shedding and hair breakage? Are these conditions normal?

     

     

     

    [1] http://www.webmd.com/skin-problems-and-treatments/picture-of-the-hair#1

    [2] http://www.webmd.com/skin-problems-and-treatments/hair-loss/science-hair#1

    [3] https://www.realself.com/question/ottawa-long-hair-regrow-after-telogen-effluvium

    [4] http://www.ahlc.org/causes-f.htm

    [5] http://www.americanhairloss.org/types_of_hair_loss/effluviums.asp

     


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