Hair loss, why does it happen?

Hair loss, why does it happen?



What causes hair loss?

So many things can cause hair loss…the lists go on and on. It can be daunting to read an article on ‘hair loss’ and figure out what might be causing you to lose your locks. In this blog, I will provide a rough road-map that can help one navigate the causes of hair loss.

#1. Is the hair loss scaring?

Figure 1. Non-scarring Hair loss

Figure 2. Scarring Hair loss

 Figure 1 shows a non-scaring pattern of hair loss (Figure 1.). Figure 2 shows a scaring pattern of hair loss (Figure 2.). It can be difficult to tell if your hair loss is scaring by looking at your own scalp with a mirror; but, signs to look for including ‘pin-cushioning’ around the remaining hair, changes in the color of the scalp skin (scaring typically is white or lighter than the surrounding skin), and texture changes in the skin (scaring typically is bound down and feels firmer than normal skin). These changes can all mean that scaring is present.

Causes of scaring hair loss include:

  • central centrifugal cicatricial alopecia
  • lichen planopilaris
  • discoid lesions of lupus erythematosus
  • acne keloidalis (folliculitis keloidalis, acne keloidalis nuchae)
  • dissecting cellulitis (perifolliculitis abscedens et suffodiens)
  • cicatricial alopecia, not otherwise classified.

#2 Is there patterning?

Figure 3. Patterned hair loss is called ‘Female Pattern Hair loss’ in women and ‘Male Pattern Hair loss’ in men. These pictures show worsening ‘Female pattern hair loss’ in women. Women do NOT go bald even at the worst stages of hair loss.

Patterning means that there is more hair loss in some areas of the scalp compared to other areas. Figure 3. shows worsening stages of ‘Female pattern hair loss,’ in women (Figure 3). Notice that even at the worse stages of hair loss, women to not go bald (Figure 3). ‘Male pattern hair loss’ in men results in baldness and a receding hair line. ‘Female & Male Pattern Hair Loss’ are linked to an androgen hormone called dihydrotestosterone (DHT). Testosterone is converted to DHT by the enzyme 5α-reductase. People with higher levels of DHT have more ‘pattered hair loss’ compared to people with low levels of DHT.

Figure 4. Round patches of nonscarring hair loss

Another common pattern of hair loss is round or oval patches of nonscarring hair loss. This type of hair loss is called Alopecia areata (AA). Most cases of AA involve small sections of the scalp and will regrow if treatment is started. People with AA should also be checked form thyroid issues because there is an association between AA and autoimmune thyroid disease.

#3 Is there excess hair shedding?

Excess hair shedding is often a sign of a condition called Telogen Effluvium. Telogen Effluvium is a normal phenomenon of hair shedding that happens after a stressful event to the body. In the normal scalp, 90–95% of the follicles will be in the anagen phase (growing phase) and the remainder (5–10%) will be in the telogen phase (resting phase). These telogen or resting hairs are regularly shed with about 50–100 hairs shed daily. Certain biologic events can push a larger percentage of hairs into the resting or telogen phase. These resting hairs are then shed. Biologic events known to cause more telogen hairs include:

  •  Postpartum- after having a baby
  •  Post-febrile- after having extremely high fevers
  •  Severe infection
  •  Severe chronic illness
  •  Severe psychological and emotional stress
  •  Postsurgical- after a major surgical procedure
  •  Low thyroid hormone and other hormone issues (e .g . hyperparathyroidism, hyperthyroidism)
  •  Crash or liquid protein diets; starvation/malnutrition
  •  Medications

-stopping Birth Control

-starting new medications: anticoagulants (especially heparin)

-antithyroid (propylthiouracil, methimazole)

-anti-seizure (e .g . phenytoin, valproic acid, carbamazepine)

-Heart medications β-blockers (e .g .propranolol)

While this bog doesn’t mention every cause of hair loss, it’s a good place to start. You may want to consider scheduling an appointment with a dermatologist to best pinpoint your cause of hair loss.

Author

Dr. Alexis Dougherty, MD Board Certified Dermatologist Mother Wife Beach volleyball player Runner From Texas Owner & Director of Kind Dermatology & Medical Spa