Hair basics

How many hair follicles do we have?

Our body has about 5 million hair follicles. Most of them are short, barely visible hairs called vellus hair.

What is the average density of the hair follicles in our body?

The density of the hair follicles depends on certain demographics.

  • Newborns: 135/cm2
  • 20-30 years: 615/cm2
  • 30-50 years: 485/cm2
  • 70-80 years: 435 /cm2

The highest hair densities are found on the scalp and cheeks. Black and Asian people tend to have a lower hair density on the body and scalp.

What is the growth cycle of the hair follicle?

In any given time, on a healthy scalp, 80-90% of hair follicles are in the inactive phase (anagen), 10-15% are in the resting phase (telogen), and the rest are preparing for shedding (catagen).

What is the duration of each phase of the hair cycle?

On average, hair follicles on the scalp stay in anagen for 2-6 years, telogen for 3 months, and catagen for 2-3 weeks. The growth cycle phases for hair on the face and body are significantly shorter. The anagen phase lasts 4-14 weeks on the mustache area, 6-12 weeks on the arms, and 19-26 weeks on the legs.

How many growth cycles can a hair follicle have?

A typical hair follicle will have 10-20 life cycles.

What is the normal rate of hair shedding from the scalp?

Shedding 80-100 hair per day is absolutely normal.

What are the layers of the hair shafts?

  • Cuticle: The outer layer that helps maintain moisture in the hair.
  • Cortex: The middle and most important layer that is made of keratin and responsible for the strength and elasticity of the hair.
  • Medulla: The innermost layer that is only found in very thick hair and comprises of loosely connected hair cells (trichocytes).

When does hair graying start?

For most people, hair graying starts in the 20s or 30s and progresses from the temple to the crown.

What are the best treatments for damaged hair?

  • The first step in restoring hair health and texture is to make changes to your diet. Having a diet rich in vitamins and nutrients will improve your body's internal functions and positively reflect your skin and hair's appearance. Be sure to include plenty of lean proteins, biotin, iron, and vitamins E, C, and A into your daily meals.
  • Unhealthy hair can weigh down new growth and cause more split ends; keeping up on regular cuts can help you stay on top of damage. If you need to opt for a more drastic cut, ask your hairstylist about different styles that work best for your features.
  • Look for shampoo and conditioner formulated with hair-supporting ingredients like protein, antioxidants, and moisturizing oils to help restore health and strength. Avoid products that contain harsh sulfates, surfactants, or salts that can strip the hair.
  • Conditioning and restorative masks are great at nourishing and smoothing hair to revive lifeless locks and radiance.
  • Masks are thicker than ordinary conditioners. When applied to the hair, they stay put so there is time for the formulas to deeply penetrate the hair shafts and fill in the gaps that develop on the damaged surface hair. After shampooing, squeeze excess water out of wet hair, apply the treatment to your hair, and gently comb through.
  • Let your heat styling tools take a break. Post-shower, gently blot your hair with a microfiber towel and allow it to air dry. Some products help form and hold your hair without any heat needed, so you can still get the same sleek and styled outcome without the damage! If you must blowdry your hair, use the lowest setting possible, and be sure to use a heat protectant product before use.
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