Q: I am 41 years old and have coarse, thick hair.  In the past several months my hair seems frizzy and breaks very easy and my hair dresser thinks my hair is thinning.  What can I do to prevent the breakage and thinning areas of hair?

A:    Human hair has a wide margin to resist stress and strain from the environment and hair treatments.  However, these forces can become excessive and damage the hair shaft.  The hair shaft has no power to repair itself as in the case of damaged skin.

To understand frizzy hair one needs an understanding of the structure of the hair shaft.  There are 2 distinct functional layers.

The cuticle is the outer layer and consists of hard flattened cells which overlap one another like shingles on a roof.  This creates a strong but flexible arrangement to the hair shaft.  The function of the cuticle is to protect the inner, more delicate cortex.  The cuticle is resistant to damage but it cannot withstand excessive environmental damage (humidity, wind, cold, etc.) or excessive hair treatment damage (drying, coloring, perms, etc.).  The number of overlapping cuticle cells (thickness of the cuticle) and type of cuticle cells varies from loose, open cells to tight, firm scales.  Also, the porosity of the cuticle cells is variable.  These are characteristics that vary from one individual’s hair to another.

The cortex makes up 75-90 percent of the hair shaft mass.  The behavior of the hair is determined by the cortex.  These physical properties include strength, elasticity, pliability, diameter, and quality of the hair shaft.

Any insult that damages the structure of the hair shaft (cuticle and/or cortex) can make the hair frizzy.  The cuticle is tough and protects the cortex, but does not hold it together.  The cortex is strong but cannot resist wear and tear.  The cortex holds itself together but is easily damaged without normal cuticle protection.

Any excessive stress that damages the cuticle layer will ultimately damage the hair cortex and cause frizzy hair.  Although there are numerous beauty treatments and environmental stresses that can damage the cuticle layer, it is of interest that both excessive dryness and excessive moisture can damage the cuticle layer.  Frequent shampooing and conditioning is necessary to keep hair clean and hygienic.  Therefore, extremely dry climates and extremely humid climates can cause frizzy hair.  If the cuticle layer is damaged one can apply treatments which can be beneficial to fix the problem.  The cuticle is used as a base for hair sprays, lacquers, conditioners, fillers, and hair cosmetics.  Repairing damage to the cuticle layer of the hair shaft will protect the cortex layer and eliminate frizzy hair.  Also over-brushing and handling the hair can aggravate frizzy hair.  There are some hair products which can aggravate or cause frizzy hair.  Gels, mousses, and hairsprays with high alcohol content should be avoided as the alcohol can cause frizzy hair.  One should not over look the fact that stress, illnesses, medications, and nutrition can have a negative impact on hair growth and frizzy hair.

Products which restore and maintain normal scalp and hair pH (shampoos that are pH adjusted), restore moisture content (conditioners), and flatten cuticle cells (pH adjusted conditioners), and products which help fill, coat, and repair cuticle cells (pH adjusted protein treatments) will prevent frizzy hair.  There are some conditioners formulated to help smooth hair.  In addition, there are deep conditioning treatments that can be used once a week to help smooth and soften frizzy hair.  Pomade and hair creams can be used to combat hair frizz.  Anti-frizz serums that contain silicone (dimethicone and cyclomethicone) help fight frizz.  Non-alcoholic mousses can be better than styling gels for frizzy hair.  Avoid hair care products that aggravate frizzy hair.  Avoid over-drying, and use styling agents with wide teeth to avoid hair static and frizz.  Remember, you can control and tame frizzy hair, not cure “the frizz.”  These products need to used repeatedly and cannot be a one-time solution.  Topical Rogaine (minoxidil) can be used to stimulate hair growth in thinning areas.