Causes of Hair Loss

Hair is an important part of a person’s appearance. A full head of hair, or lack of it, is one of the first things people notice about us. Poorly done hair transplants (known as the “pluggy” look) or attempts to hide baldness like “combovers” and obvious toupees, make the issue stand out even more. Attempts to hide hair loss reveal how healthy, full hair is revered in our society.

Common causes for thinning hair include: heredity, hormonal changes like testosterone turning to dihydrostestosterone, or aging.

At our peak in our early teenage years, humans average about 100,000 hairs on their heads. Individual hairs grow for a period of 2-6 years. It is normal for about 100 hairs to shed naturally every day, most of which enters into a resting phase (telogen) for about 3 months. A new hair growth cycle begins after this time, but factors such as aging, disease, and hormonal changes can affect each succeeding cycle.

Most Common Cause of Hair Loss – Hormones

The most common cause of hair loss is due to hormones, specifically the hormone dihydrotestosterone (DHT). Hormonal causes of hair loss is commonly called pattern hair loss, and is medically known as androgenic alopecia.  Dihydrotestosterone is created when the hormone testosterone interacts with the enzyme 5-alpha reductase.  While testosterone is commonly associated as a male hormone, it is also present in women in smaller amounts. In men, DHT is the most common cause of hair thinning that leads to eventual hair loss. Hair grows in a cycle: growth-shed-rest-repeat cycle. In men, DHT-sensitive hair follicles grow back progressively thinner hairs in each cycle. In women, the cause of hair thinning is more undetermined, but evidence suggests that DHT causes inflammation that leads to hair thinning. Everyone has dihydrotestosterone in their system, but not everyone is DHT-sensitive . The difference of most people suffering from pattern baldness is not the amount of DHT they have in their system, but if their hair follicles are sensitive to it. Those who have DHT-sensitive hair follicles will experience pattern hair loss to varying degrees.

DHT causing hair to thin

DHT causes hair loss in most cases of male and female pattern hair loss

Androgenetic Alopecia/ Pattern Hair Loss

Pattern hair loss (pattern baldness), is scientifically known as androgenetic alopecia. It is the genetic predisposition that affects both men and women in losing hair that is responsible for 95% of all hair loss cases.

Male pattern hair loss/ male pattern baldness (MPB) consists of the receding of the frontal hairline, and loss of the hair at the crown/back of the head (AKA the bald spot). Affected hair areas are susceptible to the hormone dihydrotestosterone (DHT) which causes hair thinning (miniaturization) that if left untreated, results in permanent loss. This does not happen to hair at the bottom/ sides of the head as this hair is genetically resistant to dihydrotestosterone.

Female pattern hair loss is different, as women tend to thin their hair and have their hair part widened (widening of the part). While the causes of female pattern hair loss is still being determined, it is likely caused by inflammation caused by dihydrotestosterone.

Treatment for DHT-Sensitive Hair Loss Sufferers

The effects of DHT on sensitive hair follicles can be stopped with TrichoStem® Hair Regeneration. Without bias, TrichoStem® Hair Regeneration is currently the best available DHT-caused hair loss treatment on the market. The drug finasteride, sold by the brand name Propecia, is an inhibitor of 5-alpha reductase, the enzyme that causes testosterone to be converted to dihydrotestosterone. However, there are several problems tied to DHT: women can not use it, it doesn’t work on all men, there are numerous studies  and reports of men experiencing long-term sexual side effects from its use (even after cessation), and it must be taken daily or hair will revert back to progressive thinning. On the other hand, TrichoStem® Hair Regeneration: can be applied to women at an over 80% success rate, works on men at over a 99% success rate, contains no drugs to cause any side effects, and is only administered once in the vast majority of patients.

Beyond DHT – Other Factors of Pattern Hair Loss

Clinical evidence shows that DHT is not the only cause of pattern hair loss. Finasteride, which prevents DHT from forming by inhibiting the enzyme 5-alpha reductase, doesn’t work on all male patients with pattern hair loss. Initial studies of finasteride claimed that the drug worked in about 80% of males over a three year period. However, an independent study that reviewed the same images of hair growth only saw the drug work in a little less than 50% of males. Medical science still cannot determine what these factors are.

However, there is good news – although these factors are still unknown, the wound-healing and adult stem cell-based treatment of TrichoStem® Hair Regeneration still works on these unknown factors of pattern hair loss. With close to to 100% of male patients noticing thicker hair growth without any signs of regression after 5 years, TrichoStem® Hair Regeneration remains the benchmark in hair loss treatment.

Other Hormonal Hair Loss Factors

Pregnancy/Postpartum Hair Loss

During pregnancy, estrogen levels are increased, which lengthens the hair growth phase and lessens the shedding phase, resulting in a thicker than normal head of hair. After pregnancy (postpartum), estrogen levels fall, resulting in an increased shedding/resting phase (telogen). This also results in less hair in the growth phase (anagen). Postpartum hair loss is temporary and normal, with hair growth cycles normalizing six months to a year after pregnancy and restoring your hair to pre-pregnancy thickness.


The hormonal changes of menopause such as the decrease of estrogen and progesterone causes a hormonal imbalance that can result in hair loss. However, it is recommended that hormone replacement therapy be closely supervised. Other factors like nutrition, illness, and medications are increased during menopause, and can also be contributing to hair loss.

Hair Loss Caused by Stress – Telogen Effluvium

Sudden and severe stress can slow new hair growth, then followed by a delayed hair shedding (telogen) phase. This results in higher than normal amount of hair entering the shedding phase at the same time, resulting in visible patches of temporary hair loss. This is scientifically known as telogen effluvium.

Hair Loss Caused by Medical Therapy – Anagen Effluvium

Medications for heart conditions, blood pressure, birth control, diuretics, acne, and depression can cause temporary hair loss as a side effect, medically known as anagen effluvium. Cancer treatments like chemotherapy and radiation also commonly cause hair loss, but patients normally restore hair growth a certain time after therapy ends. Exposure to various chemicals can also cause anagen effluvium.



Fungal, viral and skin infections can cause hair loss or thin hair. Proper diagnosis, medication and proper infection treatment can solve temporary hair loss issues.


Serious disease such as lupus, diabetes, and thyroid disease can contribute to hair loss. After proper diagnosis and medical treatment to alleviate the bigger issue, the TrichoStem® Hair Regeneration non-surgical treatment can be used to restore hair growth, thicken the thinned hair, and prevent further loss.


Hair loss is most predictably a genetic issue – people with family members who have suffered from hair loss are likely to have it themselves. It is important to disclose your family’s history with hair loss when having your own situation evaluated.


The likelihood of hair loss increases with age. The likelihood of hair loss can be predicted by the Rule of Decades – once in their 30s, 30% of men experience hair loss; by their 40s, 40% of men are experiencing hair loss, etc.

This rule is different for women – about 30% of women under the age of 50 experience hair loss, while about 50% of women over the age of 50 experience hair loss.

Nutrition Deficiencies

While poor nutrition rarely causes hair loss, it can cause hair shafts to become brittle and break off.


Air pollution from industrial/urban pollution, and exposure to cigarette smoke can contribute to hair loss. This was cited by a study done at the University of London.

Hair Loss Syndromes


Alopecia Areata

Alpocia areata is an immune system disorder that causes hair follicles to stop producing hair. Common symptoms include small bald patches on the head.

Advanced forms of alopecia areata include alopecia totalis, where all hair on the head is lost; and alopecia universalis, where all body hair is lost.

Traction/Scarring Alopecia

This caused by the intense pulling of the hair, normally from tight braids and corn rows. The hair follicles get stressed from the intense and prolonged pulling, leading to follicle damage and hair loss.




A disorder where a person compulsively pulls out their own hair, resulting in noticeable hair loss. While trichotollomania can happen in children of both sexes, in adults it happens almost exclusively with women.This is more of psychological problem that should be treated with psychological treatment rather than hair loss treatment.

Lichen Planopilaris

Lichen planpilaris is a rare inflammatory condition where there are patches of permanent hair loss in the scalp. It affects mostly young women, but can affect men and can have wide age range. It is characterized by smooth patches of the scalp without hair growth.

Trichorrhexis nodosa

A defect in the hair fiber characterized by fraying and swelling nodes on the hair shaft that make it easily broken. It is a reaction to repeated and excessive trauma such as application of hair chemicals, extreme styling, and long and repeated ultraviolent exposure.


Folliculitis is the infection of the hair follicles by bacteria, fungus, or yeast. Common causes include exposure to unhygienic hot tubs and swimming pools. It can also occur from wearing tight clothing that irritate the skin and the hair follicles, or chemicals or sweat that can block and injure follicles. Hair follicles that are injured are more likely to be infected. Infection can also occur from cuts, scrapes and wounds that affect the hair follicles. With so many possible causes, folliculitis is common, but can be readily treated with over-the-counter, prescription, and even common homemade remedies like white vinegar.

At TrichoStem® Hair Regeneration, we are always ready to help you diagnose the cause of your hair loss. Call us at (212) 265-8877 in Manhattan, New York City, or (516) 742-4636 in Garden City, Long Island, or in our Vienna, Virginia location at (), or fill out the contact form below and we’ll get back to you.

Schedule An Appointment Today!

To schedule a consultation with Dr. Amiya Prasad or a TrichoStem® doctor, submit the form below or call our Manhattan office at (646) 461-8547 or Garden City Long Island Office at (516) 535-9479. Our phones are open 24 Hours a Day / 7 Days a Week. Virtual consultations through Skype or through sending your hair loss details are also available. Patient Financing options available for qualified candidates.

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