How is Hair Loss (Baldness) defined?

All normal men and women lose scalp hair every day which averages between 25 to 100 hairs per day. Some individuals can normally shed up to 150 hairs per day. When hair loss is increased compared to daily baseline hair loss or it occurs in patches then it is abnormal. Abnormal hair shedding or bald areas on the scalp constitute a hair loss disorder, which is also known as alopecia. Hair usually becomes thin and weak (miniaturization) before there is a complete loss.

Why is Hair Loss Important?

Hair loss isn’t only just cosmetic. Hair loss can have detrimental psychological effects. Studies have shown that hair loss can be associated with low self-esteem, depression, introversion, and feelings of unattractiveness. This is particularly true in Western societies and increasing true in Eastern societies. Generally, economically developed countries place great value on youthful appearance and attractiveness. Some studies have shown that based on appearance alone, men with hair loss (as well as other features) are seen as less attractive, less assertive, less likable, and less successful than men without hair loss.

How prevalent is Hair Loss?

  • Studies have shown that more than 50 percent of all men over the age of 50 will be affected by male pattern baldness to some extent and up to 80% of men age 70.
  • Studies have shown about 25 percent of all women at the age of 50 will be affected by female pattern baldness to some extent and up to 42% of women by age 70.
  • Hair loss in Caucasians is more prevalent than in blacks or Asians.

Hair Physiology

The lifecycle of a hair follicle occurs in 4 phases:

  • Anagen
  • Catagen
  • Telogen
  • Return to Anagen


This is the active growth phase of the hair follicle and may last 2-6 years.


This is the transition where the hair follicle and bulb begin to separate from the hair papilla and start the migration up to the skin before shedding. This phase usually lasts 1-2 weeks.


This is the resting phase where the hair follicle has fully separated from the dermal papilla and usually lasts 6 weeks to 3 months.

Return to anagen phase:

Dermal papilla and hair matrix forms a new hair follicle.

What are the Causes of Hair Loss?

There are many causes of hair loss. The two most common types are male pattern hair loss and female pattern hair loss, each represents a different hair loss pattern.

Male Pattern Hair Loss (androgenetic alopecia)

This is the most common hair loss pattern in men and is characterized as nonscarring diffuse hair loss evolving from progressive miniaturization of hair follicles and consequently progressive reduction of total hair count and thickness primarily involving the frontal and central scalp areas, and extending laterally.

Male pattern hair loss is an inherited genetic condition related to that individual’s hair follicle sensitivity to the effects of dihydrotestosterone (DHT) in some areas of the scalp. DHT is believed to affect the anagen phase of the hair cycle causing a shortening from a usual duration of 3–6 years to just weeks or months. The genetic predisposition comes from either parent or from both parents.

The male hair loss pattern differs from female pattern hair loss. Hair loss begins above both temples and over time, the hairline recedes to form a characteristic “M” shape. Hair also thins at the crown (near the top of the head), often progressing to partial or complete baldness.

Female Pattern Hair Loss (androgenetic alopecia)

This is the most common hair loss pattern in women and is characterized as nonscarring diffuse hair loss evolving from progressive miniaturization of hair follicles and consequently progressive reduction of total hair count and thickness primarily involving the frontal and central scalp areas, and extending laterally. Hair loss in women tends to be less severe and rarely leads to total baldness. Women tend to maintain their frontal hair line and is more diffuse. Male pattern hair loss can occur in women but is uncommon. Hair loss in women is more complex involving more genetic influences and is multifactorial including additional influence of environmental factors. Various possible hormonal influences include androgens, estradiol, progesterone, thyroid hormone, hormonal changes of pregnancy or menopause.

Other causes of hair loss include:

  • Thyroid dysfunction
  • Post-partum
  • Nutritional deficiencies such as Iron, Zinc, protein, or Vitamin D deficiency
  • Rapid weight loss
  • High-stress levels or major life events causing emotional and hormonal changes
  • Inflammatory conditions causing scarring of the hair such as folliculitis, infection, lichen type changes, lupus
  • Secondary scarring from traumatic scalp injuries, surgery on or through the scalp, keloids, burns
  • Medications such as beta-blockers, ACE inhibitors, high doses of Vitamin A, low molecular weight heparins (enoxaparin, dalteparin), warfarin (rare), lithium, SSRIs (eg fluoxetine/Prozac), Retinoids (Acetretin, Isotretinoin, Vitamin A supplements), antimicrobials (Isoniazid, Antiretrovirals like Indinavir)
  • Chemotherapy
  • Autoimmune causes
  • Traction on hair roots such as tight braids, glued hairpieces, or anything where the hair is pulled tight
  • Trichotillomania (obsessive-compulsive behavior) caused by excessive pulling on their hair (usually children or teens)
  • Excessive pressure to an area of the scalp such as a type of pressure sore
  • Radiation-induced
  • Infections such as Syphilis, bacteria, fungus (tinea capitis) or untreated ringworm of the scalp
  • Scalp conditions causing itchy scalp, hair loss, and flaking repeated scratching such as dandruff or seborrheic dermatitis


Male or Female pattern hair loss can mimic and often runs concurrently with other health problems that may affect hair loss. A detailed medical history and physical examination are necessary.

It is easier to treat hair loss early when the process is starting and hair structures are still present but dormant than when the hair structures are absent and dead. The earlier treatment leads to better results. Both male and female pattern hair loss is not cured in a “one and done” treatment. It requires lifelong treatment. Any break in treatment will begin the hair loss process.

Current treatment options include:

  • Hair replacement / transplantation
  • Cosmetics
  • Micropigmentation (tattoo) to resemble shaven scalp
  • Hairpieces
  • Minoxidil solution
  • Finasteride tablets (type II 5-alpha-reductase inhibitor)
  • Dutasteride
  • Platelet-rich plasma
  • Microneedling
  • Low-level light therapy
  • Stem cell therapy

This section will describe the last 6 options.


The medications listed (Minoxidil, Finasteride, & Dutasteride) have the potential to cause fetal abnormalities and are thus contraindicated in pregnant women or women trying to become pregnant. Those three medications affect androgen metabolism or its effects. The use of medications is the cornerstone of male or female hair loss treatment. These are FDA approved medications.


Platelets are rich in numerous growth factors that are released upon platelet activation (injection into the scalp). The growth factors activate stem cells in the bulge area of follicles, encourage the growth of existing hair, as well as encourage the formation of microvascular networks improving circulation and eventually providing with the nutrients required for hair growth. Clinical studies have proven the effectiveness of PRP therapy in hair loss.
Typically 3 to 5 sessions are performed in the desired area within the 4- 6 months. Injections can range from every 2 weeks to once monthly. Then booster treatments are performed every three to six months to one year thereafter. Studies have shown that the hair regrown from PRP can last for up to 18 months after treatment, I recommend once yearly boosters to keep the regrowth.


Microneedling is a minimally invasive dermatologic procedure in which fine needles are rolled over the skin to puncture the top layer of skin (stratum corneum). The physical trauma from needle penetration induces a wound healing cascade with minimal damage to the epidermis that induces collagen formation, neovascularization, and growth factor production of the treated areas. Microneedling has shown promising results as an adjuvant treatment with existing techniques.


Low-level light therapy (LLLT) is a relatively new technique in the treatment of hair loss. The biochemical mechanisms are not completely understood but the cellular respiratory chain of mitochondria probably absorbs the light energy, which results in increased electron transport and the promotion of cellular signaling and in turn allows for hair regrowth. LLLT efficacy is still being studied. It seems that LLLT in the 650 to 900 nm wavelength at 5mW may be a therapeutic option for patients with male or female pattern hair loss.


Adipose-derived stem cells show much promise in hair loss treatment. Adipose-derived stem cells are multipotent cells that have shown potential for regenerative medicine. Adipose-derived stem cells not only differentiate into mesenchymal lineage cells but also secrete various growth factors. Recent studies have reported that adipose-derived stem cells promote hair growth via growth factor secretion. We have already used adipose-derived stem cell-conditioned medium to treat alopecia and reported good results.
Reference: Hair Regeneration Treatment Using Adipose-Derived Stem Cell Conditioned Medium: Follow-up With Trichograms, March 2015.