Tag Archives: hair cycle

Understanding hair fall

We have all, at one point in time, dealt with excessive hair fall that alarmed us enough to either self treat with DIY/home remedies or to seek a dermatologist’s opinion.

Let us understand the normal physiological process that our hair goes through which is called “Hair cycle”.

Hair cycle is divided into 3 main phases :

  1. Anagen (90% of the hair are in this active growing phase ) which proceeds to:
  2. Catagen (resting phase), which then progress to :
  3. Telogen (regressing phase)–> the hair then eventually falls out (exogen) as the hair follicle enters a new anagen phase.

As you can see that as new hair grows, the existing hair in that particular hair follicle has to fall out. So hair fall should not necessarily alarming, and this normal hair shedding is seen to be 50-100/day and in some individuals it could be upto 150/day as well.

When to seek a dermatologist’s opinion?

When the hair fall exceeds what was mentioned above, or you start noticing recession of the hair line or thinning of hair in crown (in men), thinning of the hair and a more visible scalp along the part line (in females), or patches of hair loss.

Common causes of hair loss:

1. Telogen effluvium: Presents with a more diffuse hair loss of >150/day. Occurs 2-4 months after any systemic illness such as infections (malaria, typhoid etc), childbirth, surgeries, crash diet, thyroid disorders, psychological stress etc.

The condition is completely reversible and the hair loss starts improving in 4-6 months once the underlying factor is corrected.

Female pattern hair loss

2. Androgenetic alopecia ( also called male pattern baldness or female pattern baldness in men & women respectively due to the characteristic pattern of hair loss). It is genetic disorder, in which susceptible hair follicles either have a higher response to the hormone testosterone, or have a higher amount/activity of the enzyme ( 5 alpha reductase) which converts testosterone into a more active form.

Male pattern hair loss

This result is the normal terminal hair (thick , black scalp hair) is transformed into vellus hair (thin, fine, light coloured hair mostly found in other parts of our body).

The overall effect is gradual thinning of hair. The disorder can be inherited from either maternal or paternal side

Image: DermNetnz

3. Traction alopecia:

Caused by the excessive constant stretching of the hair shaft from hair styling such as tight braids/ ponytails

4. Alopecia areata: Considered an autoimmne disease normally seen in children and presenting with localised patches of hair loss, rarely it can affect adults and be of a more diffuse nature.

Usually self limiting i.e hair regrows back even without treatment.

There are more causes of hair loss, but the ones mentioned above are the commonest ones experienced by individuals.

Treatment for the different types of hair loss may vary with some requiring no specific treatment at all such a telogen effluvium whereas others have specific therapy such as alopecia areata and androgenetic alopecia.