Facts

Some Facts About Hair Growth

Three Stages of Growth – Hair grows in three stages – the Anagen stage where hair is actively growing, the Catagen stage where hair starts to break down, and the Telogen stage where the follicle rests before resuming growth. Because hair grows in three stages, you never have a full head of hair. At any one time you only have around 85% of your hair on your head. The rest is in the Telogen or resting stage.

Structure of Hair and Hair Follicles – Hair is made of keratin. It is arranged in three layers, an outer cuticle, middle cortex and central medulla. It grows from a follicle under the scalp. The walls of the follicle form the outer root sheath of the hair. The lower part of the follicle forms the hair bulb that contains the source of hair growth. The dermal Papilla is dermal tissue at the follicle base that provides a network of capillary blood vessels to supply oxygen, energy and the amino acids the hair needs for growth.

Typical Hair Loss and Replacement – The average number of hairs on the scalp of an adult is 100,000. As we age, our hair grows more slowly and thins. The pigment cells also experience a decrease in activity causing our hair to lose its color resulting in grey hair. The average daily loss of hair on the scalp is between sixty and one hundred hairs. If the loss is over one hundred hairs daily, hair loss will exceed replacement, and you eventually become bald.

Health and Hair Loss – Hair growth is tied into the functioning of the entire human organism: body, mind and emotions. It stands to reason that whatever adversely affects the body, will, in the long term, adversely affect the hair as well. Therefore, health plays a very important part in hair growth. It is very important to rule out any medical conditions before pursuing hair loss treatments. Check with your doctor or endocrinologist before deciding to try a treatment.

Female hair loss is different from male pattern baldness. Below is the Ludwig Scale which represents different stages of female baldness.

Possible Causes of Female Hair Loss

Iron Deficiency and Medication – The use of some medications (chemotherapy, arthritis, and acne drugs) may lead to hair loss. The hair that is lost during the treatment may or may not return. Chemo-therapeutic drug-related hair loss returns after treatment ends, but hair loss due to Accutane may not return.

Hormones – Hormones that affect hair loss and growth are not just limited to estrogen and testosterone, but also include thyroid aldosterone and aldactone. It is important that you rule out hormone level irregularities because the treatment is usually taken care of rapidly, inexpensively and stops the effects of continued hair loss.

Hypothyroidism - Low thyroid levels have been associated with hair thinning and hair loss.
DHT - This is said to cause follicular miniaturization which causes the hair shaft itself to thin so hair looks fragile but no one knows exactly how this mechanism works.

Stress – Everybody’s body reacts differently to stress. Loss of sleep, lack of nutrition and lack of vitamins all lead to depletion of essential vitamins and elements that can affect hair growth and/or loss.

Genetic – This is more common among men, but can also affect women. Usually a recessive trait is carried by the mother and passed on to her son(s). For a woman to have pattern baldness, she must have the recessive trait from both her mother’s and father’s sides. Various patterns occur from crown only to full-head baldness.

Traction Alopecia – Due to excessive pulling of the hair against the scalp usually caused by ponytails, cornrows, braids, wig clips, etc.

Trichotillomania – Twisting and bending of the hair at the scalp until it breaks. If hair is pulled out at the root, over time, baldness may occur.

Iron deficiency – This is a very common cause of hair thinning and affects women of childbearing age who may experience the deficiency due to menstruation.

Alopecia Areata – This autoimmune disorder attacks a body’s hair as if it were a foreign body causing it to fall out.

Fungal Infections – Fungal infections can indirectly cause hair loss because these infections or mycoses (including histoplasmosis, coccidiomycosis or blastomycosis) are treated with a medication known as fluconazole. The strength of the dose combined with the length of treatment results in hair thinning and loss. This usually reverses itself within six months of decreasing the dosage or discontinuing the treatment.