Hair Loss

Everyone loses hair. It is normal to lose about 50-100 hairs every day. But these hairs are normally replaced as they are shed. If you see bald patches or notice a significant change in your hair density, you may be experiencing actual hair loss.

There are many causes for hair loss. Women may notice hair loss after giving birth. People under a lot of stress can see noticeable hair loss. Some diseases and medical treatments can cause hair loss. The most common form of hair loss, androgenetic alopecia (AGA), also called pattern balding or pattern hair loss, affects at least forty million American men and more than twenty million American women. Pattern balding should not be confused with alopecia areata, a completely different disorder which commonly involves patchy hair loss.

Extreme forms of alopecia areata include alopecia totalis which may involve the loss of all head hair, and the most extreme form, alopecia universalis wherein all hair from the head and the body is lost.

The incidence of androgenetic alopecia is driven by genetics, age and, to a lesser extent, environment. Environmental factors do not seem to affect AGA to a large extent. One large scale study in Maryborough, Victoria, Australia showed the prevalence of mid-frontal hair loss increases with age and affects 73.5% of men and 57% of woman aged 80 and over. Approximately 25 percent of men begin balding by age 20; two-thirds begin balding by age 60. It is believed that there is a 4 in 7 chance of inheriting the genetic predisposition for pattern hair loss.

In men, pattern hair loss is characterized by hair receding in a bi-temporal progression colloquially described as a receding hair line. Receding hairlines are usually seen in males above the ages of 20 but may be observed in the late teens in some cases.

Also, a thinning area may develop in the vertex scalp. Both balding areas may meet resulting in almost the entire scalp being denuded of hair. The trigger for pattern hair loss is dihydrotestosterone (DHT) a key metabolite of testosterone (T). Aside from contributing to pattern baldness, DHT has also been linked to several other disorders including BPH (benign prostatic hyperplasia).

The mechanism by which DHT operates is not yet fully understood. In genetically-susceptible individuals, DHT is believed to initiate a process of follicular miniaturization. Through this phenomena hair shaft caliber is progressively decreased until being reduced to vellus (peach fuzz) consistency.

Historically, it was commonly believed that baldness was inherited from one's maternal grandfather. Recently, it has been compellingly shown that both parents contribute to their offspring's likelihood of experiencing pattern hair loss. Due to a number of genetic factors, it is thought that inheritance of baldness susceptibility genes is [autosomal dominant with mixed penetrance]. This means that both alleles contribute to phenotype, but clinical expression is variable. Work continues to determine the underlying genetic basis for AGA.

Treatments for the various forms of hair loss have achieved demonstrable success. Some hair loss sufferers make use of objectively tested oral / systemic treatments including finasteride (Propecia®) and dutasteride (Avodart®) and topically / locally applied minoxidil solution (Rogaine®), in an attempt to prevent further loss and regrow hair. Recently, published studies have shown that naturally-based 5-alpha reductase inhibitors combined with blockade of inflammatory processes (i.e. Hair Genesis ®) represents a novel two-pronged approach in the treatment of AGA with improved efficacy over current drug-based modalities.

Regardless, as a general rule, it is thought that it is presently easier to maintain existing hair than it is to regrow hair once it has been lost.