What is Hair Loss?

Did you brush your hair this morning and find a few strays lodged in your hairbrush?  Don’t panic!  This is normal.  In fact, hair loss is normal in all humans.  All men, women, and even children have a normal degree of hair loss at any given time.

What is Hair?

What makes up that tiny strand of hair and how does it grow?  Hair is comprised of layers of amino acids called keratin, a type of fibrous protein.  Each hair shaft grows from a hair follicle and begins its growth beneath the epidermis, or the surface of the scalp.  A strand of hair is constructed cell by cell at the lower end of the follicle in the bulb, and it moves up through the hair root beneath the skin at a rate of about .4 mm per day, or 1 centimeter per month.

How Does Normal Hair Loss Occur?

Human hair growth and replenishment is similar to a bird that sheds its feathers through molting.  As each dead feather is lost after its life cycle, a new one grows in its place.

Human hair growth is similar.  Each human hair strand has a life cycle between 2 and 6 years.  After that life cycle, a hair strand will have a period of rest, which lasts about 2 to 3 months.  At the end of that resting period, the hair is shed and a new one grows in its place.

While about 90% of your hair experiences growth at any one time, the other 10% is in a state of rest.  That is why you may find a hair or three in your comb every day.  It is through this normal life cycle that we shed old hair tissue while keeping a seemingly full head of hair.

What Causes Abnormal or Extreme Hair Loss?

Some men, women, and even children experience excessive hair loss.  Hair loss may be only temporary and due to certain conditions, but oftentimes hair thinning is permanent.

Temporary hair loss may be due to any of the following:

  • Illness or disease
  • Extreme stress or surgery
  • Medication
  • Hormones
  • After giving birth
  • Improper hair care

A temporary extreme hair loss case is usually caused by a large amount of hair in a resting state because of one of the above issues.  The resting hair then falls out at its normal 2 to 3 month pace, but because it falls out in such greater numbers, an extreme hair loss pattern occurs.  Usually temporary hair loss returns to normal.

In contrast, permanent hair loss is found mostly in men due to genetic pattern hair loss, or male baldness.  A few women may experience genetic baldness as well.  A genetic trigger causes hair to begin receding into a “pattern” on the top of the head at a certain age.

Other permanent causes of hair loss are due to damaged scalp or scarred hair follicles.  Chemical treatments or excessive pulling of hair into styles like pigtails, cornrows, or hair rollers is most often the cause of damaged or scarred hair follicles.  Sometimes this type of hair loss can be reversed and hair will grow back to normal if improper hair care behaviors are changed.