The average scalp has 100,000 hairs. Each follicle produces a single hair that grows at a rate of half an inch per month during the normal hair growth cycle (1).

An image showing the normal hair growth cycle

Only about 10% of the strands are in transition or resting phase at any one time. Hair grows about 6 inches a year for most people.

According to the American Academy of Dermatology, most people lose anywhere from 50 to 100 strands of hair each day (2), and up to 250 strands when hair is washed. 

Because female hair tends to be longer, women notice when significant hair loss occurs. They will observe hair on their pillow or lots of hair in their comb when styling which becomes exaggerated when abnormal amounts of hair loss are occurring.

More than 50% of women (3) report significant hair loss or thinning at some point in their lives. This means that hair loss will affect 40 million women. 

What Does Hair Loss in Women Look Like?

Because there are numerous causes of female hair loss, the patterns of hair loss in women vary.

Androgenic Alopecia (AGA) 

AGA or female pattern hair loss is due to genetic causes. Women who experience AGA notice decreasing volume of hair and general thinning of hair on the top of the scalp or the temples, while the front hairline does not recede. The diagnostic “pull test” will be negative in this type of hair loss.

Female hair loss patterns

The Savin scale (1992) (4) is used to document female hair loss patterns. Unlike men, who tend to recede from the forehead or the crown of the head, women tend to notice thinning on the top third to one half of the scalp, while the front hair line remains intact. 

Alopecia Areata

Alopecia areata (5) is an autoimmune disease, which occurs when the body’s own immune system mistakenly attacks healthy hair follicles and destroys them. This type of hair loss is characterized by:

  • Patchy, bold spots. You will notice small, round, smooth, bare patches on your scalp. 
  • “Exclamation mark” hairs: Often, short hair grows on the edges of the bald spots, narrower at the bottom, like an exclamation mark.
a woman with Alopecia Areata
Source:C. CAROLYN THIEDKE, M.D., Medical University of South Carolina, Charleston, South Carolina. Am Fam Physician. 2003 Mar 1;67(5):1007-1014.

Alopecia totalis

Alopecia totalis (6) is the advanced form of alopecia areata, where a person loses 30%-50% of their hair within a month. This type of hair loss is characterized by complete baldness of the scalp. The diagnostic “pull test” will be positive.

Woman with Alopecia Totalis

Anagen Effluvium Caused By Cancer Therapy

Anagen effluvium (7) is often due to chemotherapy. After 2 weeks of chemotherapy, approximately 90% or more of the hairs can fall out while hair is still in the anagen phase. Good news? Hair grows again as soon as the cancer treatment is over.

Woman with Anagen Effluvium

Fungal Infections

Ringworm (8) is a fungal infection that can affect the scalp, triggering a distinct pattern of hair loss that occurs in itchy, round patches. Bald areas can appear scaly and red. The fungus may be visible with the naked eye or could be seen after a biopsy.

woman with Ringworm
Source: Shy, R. (2007). Tinea Corporis and Tinea Capitis. Pediatrics In Review, 28(5), 164-174. doi: 10.1542/pir.28-5-164

Traction Alopecia

Traction alopecia (9) can be caused by certain hairstyles, such as cornrows, or tight ponytails and certain treatments such as hair dyes, chemical treatments or flat irons. It is more common among African Americans.

woman with Traction Alopecia

Patterns of traction alopecia may include:

  • Receding hairline around the forehead, temples or back of the neck
  • Wide hair parting
  • Redness, itching, scars, pimples on the scalp
  • Patches of broken hair
  • In more advanced cases, patches of scarred skin

Trichotillomania

Trichotillomania (10) is a psychological condition that causes a person to compulsively pull hair from the scalp, eyebrows, or eyelashes. The pattern of this hair loss is characterized by patchy, possibly scarring spots on the scalp.

Woman with Trichotillomania

Scarring Alopecia

Scarring alopecia (11) causes hair loss that is possibly permanent and irreversible. This pattern of hair loss is characterized by the destruction of hair follicles which are replaced by scar tissues and atrophy of the skin. Scarring alopecia can be associated with other medical conditions, such as lupus.

woman with Scarring alopecia
Source: Bender, A., & Cohen, B. (2013). Chapter 8 – Disorders of the Hair and Nails. Pediatric Dermatology, (4), 211-239. doi: 10.1016/B978-0-7234-3655-3.00008-4

Take Away Message

A variety of causes are behind female hair loss. Hormonal shifts, genetics, stress, diet, and medication are just a few of the triggers of hair loss in women. That is why it is important for women suffering from thinning or falling hair to undergo a comprehensive evaluation including medical and lifestyle evaluation to identify the chief complaint, determine root causes and rule out risk factors is undertaken. The Hair Loss program at Ruthie Harper MD evaluates ALL of the factors that lead to female hair loss and creates a customized and integrated approach that provides you with the most effective solution designed just for you.

Sources:

1 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4755418/

2 – https://www.aad.org/public/skin-hair-nails/hair-care/hair-loss-vs-hair-shedding

3 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2684510/

4 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4812885/

5 – https://www.aad.org/public/diseases/hair-and-scalp-problems/alopecia-areata

6 – https://www.ncbi.nlm.nih.gov/pubmed/28378336

7 – https://www.ncbi.nlm.nih.gov/books/NBK482293/

8 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1125423/

9 – https://www.ncbi.nlm.nih.gov/books/NBK470434/

10 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5328413/

11 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3855115/